I played Sassy a few times the past two days at pound. If you started this discussion before this weekend I would have been more inclined to ask Nick Riddle to play a few games.
I also think that Pit has this matchup at least 55:45
Although, the kid is a troll we can **** ZSS at the beginning if we're smart. Those armor pieces are VERY strong projectiles and she can't use them on us lol. We can spam her with arrows to keep the pressure on then go for the armor ourselves. If she has one in her hand we can pretty much approach with angel ring and she can't do anything. Then we can grab the pieces for ourselves and use our amazing glide toss combos.
Arrows destroy her game so much. ZSS is easy to run away from. Her close range game relies on her dsmash combo's which we can avoid if we just stay out of her way or roll behind her. Her jab combo is good, she usually uses that after dash attack so if you don't shieldgrab the dash attack fast enough expect jabs. Her utilt is pretty much a gtfo move since it's almost as fast as ours, frame 3 I think.
Maharba was right about her side b. This weekend was my first time playing a ZSS offline and it's easily telegraphed, I mirror shielded it a couple times. Side b has so much reach and great knockback so she spams it a bunch to get kills, but the kill part of it only hits mid-range so stay the **** away or get in close and take minimal damage and we can avoid that too.
ZSS randomly uses neutral b to get in stuns, but we can reflect that too so no problemo.
Predict when she's going to grab and spot dodge it and gives us a free anything.
I disagree with Maharba about gimping a ZSS. A good ZSS won't waste jumps like that because they know we're trying to gimp them away with arrows. They can pretty much eat them or airdodge the arrows until they are in tether range where they have options. FF bair will get their tether recovery if they just hang there and since the hitbox stays out it will gimp her even if she tries to pull up. Still, that being said good ZSS's can get back on stage just fine.
The only thing I think that she shuts down is our planking game. We are safe if we arrow plank and she is far from the stage, but we can't uair plank. If we uair plank she can charge a dsmash and get us with that. If we're stunned in that position then its either a bair stage spike or a down b spike. Not good.
Other than that we win in the air. Her uair is very quick, but we can avoid that by moving to the side in the air. Her bair has good enough knockback to kill as well, but our bair is better. She barely uses nair, and usually only fairs if she gets a dsmash stun in and she never dairs because that has terrible ending lag. Her down b on stage is slow and can be easily punished, but it has killing power and the hitbox stays out for as long as she is in that sexy mid air pose.
So yeah, 55:45 us.
btw angel ring works well against her, I think the only thing she can do is try to grab it or side b which we should see coming in time anyway.