So going by that "Japanese tier list", my overall thoughts on Marth/Lucina's spread with those 'top characters':
https://game8.jp/matome/14157
1.
Sheik
Likely bad, but not unwinnnable. Risk/reward will be severely in her favour IMO, just like Melee, but without us being able to figure out how to crouch cancel grab all of her **** to make the match up more even at top level. In a lot of my rants on viability, Sheik was in my mind. Solid range and speed, mobility capabilities that trump us - extremely competent at running away and being aggressive, her set ups and follow up strings are consistent and that disparity will become noticeable with her punishments/reads on us getting her a lot more than vice versa. Lost the ability to freely gimp/edgehog her. Stuff like down tilt will be a struggle for her in the grand scheme of things, but I feel we need more. Will probably end up being in our top 5 worst match ups.
2.
Yoshi
Secretly a hard match up in Melee, a character we destroy in Brawl if they chose to fight us; but at top level they have sufficient run away + safety in their run away to overcome Marth's superior tools. In this game? awkward. Yoshi is still a melee focused character, however he is susceptible to having his double jump stolen and we may have the tools to achieve that. Amidst all of his "bugs", we could really really struggle. I could see it going anywhere match up wise, but I think the ball is in yoshi's court (Yoshi one of those characters I listed pre-release as a potential problem); being able to jump armor through our combos/strings/pressure could consistently counter our zoning/spacing games, being able to jump OoS for yoshi was a significant capability buff.
3.
Rosalina
A good match up for us. Although yet to face the fear of a competent one I think all the signs are there for us to be strong/able to achieve it. Rosalina's height and weight is a sore thumb for her against Marth, Marth fair is extremely good in this match up due to this. How we deal with her spacing wise/match up wise will be akin to how we dealt with Snake in Brawl. I think her immediate vertical options are subpar and her dash attack is very easy to space around in the air (imo). Falling neutral air (just like against Snake) will be a struggle for her to deal with.
Furthermore she's a character you cannot grab, and Marth no longer has a grab game to worry about this shortfall as much. Furthermore Luma is an entity our character is more than capable of dealing with.
I'm confident we can achieve some parity with her.
4.
Greninja
A rushdown character I don't know enough of other than "kinda like Sheik". Played against it a little bit, and I'm not as worried about him as Sheik as a result. Greninja does not look like he has a flip side camp game that wrecks us, nor specific aerials/normals which by design break through our zoning. Nothing I've seen that will be consistently able to out do proper usage of down tilt. It really depends on how hard this guy ****s us when he gets a hit, I just don't know yet.
5.
ZSS
In Brawl this match up was in our favour IMO (but was arguably even or slight advantage ZSS). A really solid keep away game, with many long-ish range set ups tools that wreck us. I struggle to see a single move we have that will be usable against her other than neutral air. We were kinda similar in capabilities in the last game, with Marth's better OoS game being his primary competitive strength that contrasted the two, but Marth's design has been hit with structural nerfs, while ZSS' design is quite the opposite. A better anti-air dash attack (fml), a frame trapping/safe/amazing projectile, reliable kill set ups that will take stocks at like 80-90%, her normals speed/range outdo us. Her down b breaks our pressure/juggle traps way too easily. We have no approach, and lack set ups to deal damage in the match up, and as we don't have the zoning tools against her, she controls the pace and we don't have a means of dealing with her shielding against us.
By design and not by some ******** game balance decisions (cough lucario), she will be our hardest match up, bar perhaps Donkey Kong.
6.
Bowser
We'll hit him twice as often as he hits as, in theory craft land. The problem is, we'll die after 4 hits, he won't die after 15-20. The foxification makes him so potent against us, as that design allows for constant trading with melee range characters, and Marth cannot win match ups in which he trades unfavourably in. I think in the long run we'll be able to make this match up possible, he still lacks disjoints, he's still big/fat, and his recovery isn't infallible. He could very easily be someone we can combo consistently. However, the sheer bowser factor of having 10 frame moves that kill at 80% on the ground and in the air is going to make this a significant struggle for keeping calm and collected in tournament sets.
7.
Lucario:
Marth can gimp this character and potentially win before Lucario gets past 50%. It'll be a very slow/campy match up for Marth at high level, similar to how he would have to deal with Dedede in Brawl. The disparity in range/kill power/punishment will be heavily in Lucario's favour. However, I don't think Lucario has a competent approach on Marth, Luc's dash attack oos will be sufficient a lot of the time, but if that's all we have to respect/expect for rush down (and rolls) we can "manage". In the long run, we'll lose tournaments sets, on a stock by stock count it's probably 6:4 in Lucario's favour, but throughout a 2 or 3 stock game I think it'll tend towards consistent losses due to stock deficit being almost insurmountable to overcome for us, and the opposing scenario being not a significant struggle for Lucario.
Sonic: Probably a disadvantage. Ran even with us in Brawl because of the sheer speed at which Sonic could cover space to punish us, primarily off of power shields. Overall he looks buffed from Brawl, and I'm not seeing this match up being having extra perks we didn't have in the last game.
Fox: Characters with fox normals beat us right? Maybe. I think we reach in places Fox doesn't like getting touched, as we've seen over multiple games. The recovery is definitely gimpable by us. Him being juggled is a lot more likely than other characters due to fall speed and lack of options (shine may stall again, but it is not something we have to respect with significant game play changes). Out of all the fox-rip offs this game, he's actually a
light weight. It'll be really interesting how our match ups with Fox/Falco/Sonic/Lucario/Yoshi/Bowser will go, as I think we'll be playing the match up in similar ways against all of them, but will just plainly lose against some but will do fine/maybe even beat others.
Wario: We should still win this match up by design, however I don't believe we get anything out of grab release anymore, which was our only reliable way of killing this fat **** in Brawl. Like this fat **** is such a fat ****.
Duck Hunt: don't ask me, I just don't know. Could be bad.