Played a lot of PM in Beast 6, and I want to share some knowledge here.
I played against Can~D's bowser and I feel like you really need to play this matchup carefully as ROB. I'm quite an aggressive ROB using a lot of boost fair >jab/d-tilt/d-smash but I definitely couldn't approach recklessly with that. Camping with laser and gyro works really well, and glide toss is really good as a movement option. A gyro on the ground seems to be a bit troublesome for bowser since he's so big and doesn't got the best way of picking it up without committing too much. Grabs are probably really good since bowser is so big and ROB got good follow-ups from grab, just watch out for the combo breaker nair. Edgeguard with lasers and down angled F-smash is really good as well. When recovering you need to be tricky, bowsers edgeguard game is one of his major strengths. In a lot of matchups you're pretty safe going high but not against bowser. His ledge jump bair is deadly and you want to avoid it at all cost, you can bait it out by pretending your going high and staying just outside range and the recover low back to the stage, it's good if you succeed. You want to watch out for bowsers nair, dair, flames, down-b and side-b when bowser is above you. All those are quite good option when bowser is coming down from above. In this matchup you want a big stage with big blastzones, like dreamland and delfinos. Stage without platforms like FD are also good since bowser gets great movement from platform stages such as Battlefield Warioland, Yoshi (melee).
I played against TDX's Kirby and i feel like it's a bad matchup but not super bad, definitely doable. the problem in this matchup is when Kirby gets in it's trouble, and your off-stage it's really rough as well. But ROB got some strengths as well. I found that pressuring with boost fair can be really good, and that you can gain on being on the offense. ROB also got big hitboxes, so nair can sometimes kill, especially if the ceiling is low. You can also camp, and laser I think is good in this matchup. Edgeguarding is tough, but you still want to challenge Kirby off stage, you don't have much risk, since he just hit you back on stage, maybe gets good stage positioning in worst case. When recovering you need to be really careful and tricky, his bair is really strong edgeguard tool, and you want to mix up horizontal and vertical boost as well as saving your jump and jumping early. If you play on stage with platforms it can definitely help. Kirby is a bit similar to Jiggs in the regard that he can't get high up quickly, so if you can you can sometimes recover to the top platform safely if he's not in a good position, and some times mix up going low when he thinks you're going to go high. You also want to avoid the hammer as it has low end lag and huge knockback. And speaking of hammer you also want to avoid grabs since ROBs tech options are garbage and Kirby tech-chases are good and if gets a good read he can hammer/F-smash/U-smash and get the stock. After playing a while I experiment a bit with platform camping. As I said above Kirby cant reach high quickly, if he wants to he'll need to use some jumps in order to do so. And he also doesn't a good u-air or something challenging platform camp so it's not that bad. the only thing is that I don't know if ROB got such good options out of it either. I guess you could try to get below him and try to u-air or n-air. Or maybe hit a nair through the platform idk. If you got a stock lead it might be an option stalling the game, testing their patience. I think stages with a low ceiling are good in this matchup because of nair and U-throw. Platforms might be good, if you play on a stage with platforms watch out for Kirby's dash attack of platform tricks/approaches. All in all it's a bad matchup but definitely doable, probably 60-40 or 65-35 Kirby's favor.
I played against TDX, and Mario and Kirby player. I got to say that I feel like this MU is in ROBs favor. We got better crouch cancel then Mario, great combos on Mario, and good edgeguard on Mario. I didn't even have any problem in this MU, sometimes if I found my self in a tough spot I could just CC D-smash and start a combo of it, seems really cheap and it worked. Use your projectiles wisely so they doesn't get reflected back at you, and that's a solid option. When edgeguarding first just your projectiles and then you can actually go out off stage and fair them. The best Mario can do is early up-b and cape, and both option doesn't do much for Mario, while the reward is really good if you get fair since it can finish the edgeguard. And if he needs to down-b to gain height, he should be dead. Go and fair or dair if he's close to you, or laser if he tries to it early. One big thing in this matchup is that ROB can live way longer than Mario does, and ROB also has solid approach options and combo game. Big stages definitely are good in this matchup, no surprise really. I think platforms can help ROB more than it can help Mario also. Probably a 60-40 matchup to ROB.
I played against a good Olimar player named GIL. This matchup is tricky. First of you want to know what every pikmin does and what attributes they got (blue got kill throws, purple has really good knockback etc.). Being a ROB and Olimar main, I didn't have this problem. You can look at the color his bulb to see what pikmin that is first in line, so if it's yellow he got a yellow first in line, and if it's grey he got no pikmins. If he got no pikmins he basically becomes completely bad, most of his moves requires pikmin to even use. The list of moves that requires pikmins are: All smash attacks, F-air, B-air, U-air, D-air, grab and side-B (pikmin throw). D-smash also takes 2 pikmin to use at it's full potential, one in the front and one back, if he only has 1 he'll only attack forward so if you stand behind him you won't get hit.
One thing about Olimar you need to know is that he got deceptively strong moves for being such a small character. Try using b-air/f-air with purple or red and you'll see what I mean. So you need to respect his airials and also his F-smash which got really good range with every pikmin except purple. What you should look for in this matchup I think is to get Olimar in the air, he has a tough time landing but on the contrary is a really solid character with stage control. Another thing you need to know is that Olimars recovery sucks. F-smash is my favorite tool for edgeguarding Olimar, a down angled f-smash covers sweetspot well. Obviosly use lasters and gyro before that to keep him away from the stage and hopefully take his double jump or airial pikmin pluck, which is a decent recovery option for Olimar. I don't think offstage edgeguard are that good in this MU, because there is a risk getting hit by Up-b and then you basically failed your edgeguard attempt, and edgeguarding I feel is ROB strongest advantage in this MU. You want to play this matchup with respect I feel, becuase boost nair/fair can easily be intercepted by fairs/f-smashes/U-smashes/nairs and U-airs. I think you should camp and wait for an opportunity to get in and then try to get Olimar in a position he's not comfortable at, in the air or offstage. I think ROB's camp beat Olimars, with laser and Gyro against pikmin throws, you can even fair and nair the pikmins which is really good at times. When recovering you want to avoid the f-smash, it's a really strong option covering low recoveries, since Olimar can F-smash offstage and the pikmin falls down and hit you. D-smash is also really strong edgeguard option for Olimar. High recoveries are probably the safest but you want to be aware of that Olimar got an excellent coverage above himself with U-airs and U-smash. ROB's Side-B can work in this matchup but it can be CCd, it probably works best if he tries to throw a white or purple pikmin. I think that a big stage with big blastzones is definitely best for ROB, you most likely KO Olimar out of edgeguards or out of juggles with U-air or N-air, and since Olimar got such strong attacks a small stage like Warioland takes away ROBs recovery since he might simply die to fair or something like that. I feel like this matchup could be in Olimars favor, or even. Olimar seem to a lot of tools to deal with ROBs approaches as well as great combos with nair to fair and stuff like that, and also a great grab and a great punish out of grab.
I played against Charby's ZSS, and first, of he's a superb player for sure, secondly, this matchup sucks. That f*cking dair is nightmare for ROB, I tried DI right and left and still got hit by like 5 of those. I talked about that with him and he said that because ROB is so big you'll still take a lot of those even with good DI. And the dair is only one of ZSS good moves. Her nair is a good combo option, her U-air is basically like Falcons, Bair and Fair can kill and has great range, and neutral b is a good projectile. But the matchup is still doable you just need to play on point. Punish hard with U-airs, and D-smashes leads to a lot, and grabs are also really good, I think you chain-grab her at low %.You can find boost fair approaches at times, as well as side-b when they don't expect at higher %, you can also reflect ZSS neutral b with it. When you edgeguard you want to use you projectiles to take out her jump and down-b, and if she needs to recover low grab ledge quickly. That's besically how you edgeguard tether characters in this game, they are forced to jump and then you can bair or nair. If the ZSS is good like Charby, she'll obviously try to tether to the ledge as quickly as possible to prevent this, and if she does you can't do much. You can try to d-tilt if they stay on the ledge for to long, throw out a gyro to cover some ground, and try to keep stage positioning. I have no clue what stages are good in this matchup. Maybe stages with platforms. A big stage probably is better because you can camp and chose when to approach, but ZSS got great movement and also lethal airials so it's not a super good advantage I feel. The ratio is probably something like 60-40 or 65-35, you can do it if you play really well and punish hard, but it's tough.