So overall, your team isn't thaaat good, and I would suggest posting an rmt on it. HOWEVER, since you only asked about the z schmoovers, here is what I got from the uu discord lel.
zera will always have the same stuff wall it barring using some tom foolery
Basically, with physical bluk up zera, you'll always be walled by the hippo, hippowdon. A dangerous defensive threat, it'll be walled eternally unless you use grass knot.
but zera in sm is generally not it
Zera isn't the best in SM UU apparently, so there's that. If you want to run zera, here is a set.
Zeraora @ Shuca Berry/Expert Belt
Ability: Volt Absorb
EVs: 252 Atk / 4 SpA / 252 Spe
- Plasma Fists
- Close Combat
- Grass Knot
- Knock Off/Volt Switch
Now, onto gengar.
you could prsumably mess around with trying to get acrobatics to work on zera with like a lum or something instead of z-bounce but cant say I'm a fan of bulk up zera in sm uu in general considering like
gengar loves the value ghostium/fightinium bring and ur alternatives of like, life orb? just give more unecessary chip you dont want
So, based off of this, I would say that gengar loves its z move more, as it doesn't need more chip from life orb. Either that, or you're running black sludge, which is like.....what. Gengar is not bulky, so uhh, yeah.
I hope this helps :)
And if you want, you can post an rmt, I'd be happy to help, and I'm sure everyone else will be too :)