Have you 3 manned Mewtwo?
I 3 manned Mewtwo today and it was a pretty fun experience. We had all three teams represented so it was easy to see how much damage each player did, I ended up in second place. The Mewtwo had confusion and psychic which is one of the easiest movesets. We were able to finish with 40 seconds left so it was a forgone conclusion, even with one of the trainers only level39 with some suboptimal counters.
Answers
I think you’re good it depends now on the moveset and the quality of your teammates pokemon. If those last Two ttars are high IV you could power them up to cover your bases. You will probably get to at least your second pokemon on your second team so you may have to go deeper. Have that second team as a preset party for sure.
Ours today was Confusion/Focus blast in cloudy weather...I'm sure I could do 33.4% damage on an easier moveset though. I have 4 more level 30 Tyranitars for a second team. ****Another Mewtwo on Saturday, a level 40 has the same pass but she doesn't shred stardust and RC like I do--her 4 M2's are level 20 til she gets the one she wants to max
My Mewtwo IVs have been bad, so three at level 30 turned out ok. My level 34 Tyranitar with with Stone Edge not ideal. Right at gym rework I took bunch of Tyranitars to level 30, should have been more selective in the ones I took there. I can talk the group on Saturday into letting my try the Mewtwo solo and I'll see how far I get, then I'll coast with the big group