Frankly, I think there might be too much Githyanki stuff here and not enough Githzerai.
Zerthimon's Champions
The Followers of the Githzerai God King
The Barmy Githzerai (Those who tend to become Xaocists and revere the power of Chaos)
Any other groups that should be detailed, you think?
The Anarchs, githzerai responsible for maintaining the Limbo cities and fortresses in a stable state.
The githzerai counterparts to the githyanki reconcilliasts.