Alright, so I play the MU similar to the fox MU, but that's just cause I don't have a lot of specific knowledge on the Falco MU and more of a general idea, which is enough for me to beat any mid level Falco in my region, higher ranking Falco? not quite enough.
KK, so CPs against Falco, it's a very style specific CP, if a Falco likes to laser a lot and run away, Dreamland is not a good idea a lot of the time.
If a Falco likes to be up in your face a lot without giving you much room to breathe and the laser game isn't that great, then I like to take them to FOD or Yoshi's, I wouldn't recommend taking a lot of characters to Pokemon because I feel like Falco really likes it there in that MU.
Sheik doesn't have as many options on that stage just because of how it's set up, Sheik needs platforms, so game 1 it's a good idea to take them to Battlefield 99% of the time.
The only time it isn't is when you come across the battlefield master, which you can't really be looking out for until you've already taken them there.
(Falco also has a lot of setups of pokemon so he gets a lot more off it than you do from my experience)
So moving onto lasers, sometimes they can be easier to deal with than other times.
When a Falco lasers a lot then you need to either know how to power shield consistently, or just get away from them.
When it comes to Falco's lasers, he's kinda playing like a shoto character, he's gonna fireball, want you to jump, he'll then DP/Anti air.
So as long as it's not FD, you should be able to needle cancel approach.
If it is FD, well then my call would be to just have a good power shield game and know when to crouch under the lasers and jump over them.
And edge guarding with side b?
You don't really need to, a lot of the time you can just F-tilt them into fair, if possible just grab edge invincible bair or fair depending on the situation and spacing, which you'll find with practice.
Sheik's chain is better for characters with softer recoveries like Falcon/Ganon's up-B
