I'll y just address two thing briefly. His recovery doesn't have a hitbox, so don't be afraid to go after him off stage and gimp with an aerial. Our Hylian shield block his arrow, so just walk or run (don't dash) towards him and his arrows are rendered useless.
I've been practicing Dark Pit lately so I'll add some stuff. Zane and I played each other a few days ago and we did this matchup (how ever many games we played)
The recovery doesn't have a hitbox, but you are not gimping that character with an aerial, that recovery goes waaayyyyyy farther than people think. If you want to threaten a Pit/Dark Pit while they're offstage, force them to sweet spot the edge (which they literally almost always need to) by chucking projectiles to force them to go low and ledge trump or condition them into thinking you're going to ledge trump and bait a buffered roll or getup. Also, they have 3 jumps which they can use to hover (basically) and can literally shoot an arrow at Link before trying to actually recover. And don't forget they can use side b (which has armor) to grab the ledge depending on how close they are.
Pit's fsmash is decently fast so be careful what moves you throw out at higher percents, because he can do fsmash OoS. Pit's ftilt has better kill power than Dark Pit's (whereas Dark Pit has harder hitting smashes I believe). Their side b also kills and are good at punishing rolls and has armor so it can actually absorb an attack (he still takes damage) and hit you. Pit's side b sends his opponent farther upward as opposed to Dark Pit who sends them more horizontally. I would think Dark Pit's would be more dangerous in this matchup since it sends you farther offstage and to more to the side. Pit is also able to punish quite a few moves with his dash attack (bomb pulls, tilts, jabs) and it sends Link up in a bad spot for possible juggles.
Both characters can easily hit Link's shins to negate the Hylian Shield. I personally find it easier to do this as Dark Pit since his arrows have a different trajectory than Pit. Walking will not render them useless, you might block one or two, but no Pit is going to stop shooting arrows, especially when he can shoot Link during bomb pulls, (if the arrow is fully charged, I believe it can actually make Link drop the bomb, I think...)
Also, Pit/Dark Pit are VERY good at punishing Link in the air since a lot of their aerials are multi hitting and have pretty good range/juggle potential so be careful when challenging with Nair or something.
At low percents, Pit can fthrow > dash attack and depending on DI he can then follow up with a Nair or usmash. He can also do dthrow combos, (Nair, dair, fair and usmash all true combo at low percent)
Pit can also ledge trump into a bair for a kill setup. And his bair is pretty powerful.
When I played Zane, he did really well when he had the space to chuck bombs, rang and arrows so Link obviously should be zoning in this matchup. He also had some tricky soft bomb setups/traps that made it a little harder to approach him (Pit has low aerial mobility so he will most likely be doing more ground approaches, if he approaches from the air it's easier for Link to hit him and throw ****).
Pit/Dark Pit do indeed have a reflector, but it can be baited out and if he does it in closer range, you can definitely punish that. Oh, also their side b also reflects projectiles.