The grasses will do more DPS than the Dragonites, so keep them. The Zapdos could be charge TM'd since Thunder is it's worse move.
I'm guessing everyone else in your group is also optimising their Pokemon which is why you're only getting 1 ball - if everyones doing more DPS, the raid ends sooner so you have less time yourself to do damage.
The person using 6 Dragonites, if they actually used all 6 of them could mean the other players were using suboptimal Pokemon, if 7 players were using optimal Pokemon, they probably wouldn't get to their 6th Pokemon.