It's not even just about Pancada deserving to be on the team or not, or Zellsis deserving to be in the 5, doesn't matter. Imo any of C9, 100T, EG (without D1 and Ethan) would be improved with the addition of Zellsis.
It's just the fact that they keep changing the roster over and over and over, how do they expect results? I'm pretty sure since the team was formed initially it hasn't been the same for 3 consecutive months at any point in its history