hi ho main here. ima address a couple things. i dont think doing a "rate" of sorts is appropriate in this thread but I still wanna help in some way
I want to start by saying screens ho atm has pretty much been fully explored and theres not much creativity in archetype. Most teams are running lando/koko/ace/mage/shifu/rker (lucha is super common here, I posted a team with those 6 above with chomp > lando) due to that being a combo that just works so well. if youre wanting to build your own ho team id stray away from the screens archetype for now but ill still post some info thats applicable to screens as well as the rest of ho
toxapex is there as a pivot to get into a pokemon after setting up screens, it doesnt seem great but it's been very useful
toxapex is a huge momentum sap for ho teams. you mention it as a pivot after setting up screens but after you use eject button, its pretty much deadweight. this issue is mostly cause of your choice of setter, grimmsnarl. koko and regi are more common and arguably better as they allow to get momentum as soon as you set screens via u turn, volt switch or explosion. your team atm also does not have a suicide lead (or rocks) so finding a mon that sets rocks would be beneficial (lando/drill/chomp). just keep in mind ho is all about keeping pressure and momentum.
sd chomp does seem good for it but it's my scarfer so i dont want to get rid of the scarf on it unless i get a better scarfer to replace it
for now
ho being so fast paced you dont even need a scarfer (with the exception of hw latias and fini due to the the rain mu). ho runs a lot of speed control mons as it is so a scarfer isnt needed. garchomp is great on ho atm as a sweeper with sd scale shot or as a offensive hazard setter/suicide lead. ho also runs a lot of mons with speed boosting moves so that makes the need of speedy scarf mons lower (however, theyre still super useful) if youre super concerned about fast mons on ho ill run down a short list of viable speed controls for ho atm; scarf latias, scarf fini, cinderace, dragapult, hawlucha, koko, kartana, spec (i dont really like this one but theres some merit in running it), blaziken (niche pick but can see more usage post shifu), terrakion (noticeably slower than the rest however it still out paces a lot of things + could be useful post shifu as well.)
for now i think im gonna add magearna & another pokemon that beats fairies, since those currently beat my entire team except toxapex
i like the suggestion of magearna as its the single most broken mon on screens at the moment (probably the best ho mon in general) and is pretty much a must. lo cinderace is incredibly good as well as it could provide a lot of utility with its variety of sets (stuff like gunk and eball are super good lures & sucker is good for additional rk ability), however, its not as much as a must gear. you could play around with the slot ace is in if you want to try something different for ho, to make your "own" team ya know. i wouldnt worry too much about fairies if you got gear behind screens, as it sets up on most of them and beats them pretty safely outside of stuff like; scarf trick fini (you can play around it), specs koko (not common), imprison clef (not common at all), unaware clef with boosting moves (not uber common, however, you can still win with gear or you should have something else to deal with it) and opposing gear (deal with it with another mon or be ahead in boosts. outside of that its a 50/50 of who has a better item to win that mu if u decide to set up on each other)
what should i replace urshifu with if it gets banned?
been looking into this personally, terrak and chicken are the first that come to mind but they both perform slightly different roles than shifu but perform part of what shifu can do. kommoo could be cool cause its kommoo
shifu overall is a hard mon to replace on ho for its ability to cover a lot of bases, I dont think the wallbreaking portion would be as hard to replace for the archetype but the RKing (priority) portion will be. Short list of shit that comes to mind; azu, rilla, ace, pult, bisharp
some more niche picks could be like conk or crawdaunt, crawdaunt atm is just outclassed by azu and conk is outclassed by shifu but is also uber slow making it a eh pick
hopefully everything I listed and said here can help you formulate your own ho team and more viable ho team or you can just steal an ho team from somebody else (theres a couple decent ones in this thread). if you decide to build one yourself, dont stick to the mons I mentioned 100%, theres a couple of cool shit I didnt mention like dragonite, hydreigon, zapdos-galar etc... ho is all about trying new things to see what works on the archetype and what next break through could become meta and refresh it for another 2 months before that gets stale. dont limit yourself to just screens as theres a bunch of cool things you can tinker with as well! (webs, hw, weather, terrain just to name a few that arent screens or rocker + 5 goons).
goodluck!