[Endoperez]

Being able to use Void gate efficiently is a special (stacking) ability, and only few commanders have it. Compare it to stealth. And no one can enter the gate without astral magic. So, the only effective summoners being Starspawn priests does not mean that other priests would do any good. And the Stargazer-hero of R'lyeh is better than the priests, or so I have heard. I don't believe the pretenders who came from Void are very effcient at summoning, or even able to.
They are not going to go back after having so much trouble getting out of there in the first place...