Volms: the new race.

A new race landed (pun intended) on Earth at the end of the second season. We've been all these months asking whether they would be allies or enemies. 

The third season has begun, and they present to us The Volm as new allies.They have brought new technologies, both for war and for healing. Collaborate in the missions and their leader Cochise (Doug Jones) is present at the meetings in the war room and is aware of the movements of Charleston.
Tom, the new president of Charleston, is convinced (or so shows us) that these new aliens are trustworthy, but Weaver does not trust even a hair. Believes that his intentions are not as noble as they do see, and he's not alone.
There is a kind of mistrust floating in the air, everybody has accepted The Volm because they are helping and do not seem to be a bother, but in truth, they are convinced that this new alliance at the end will bring more problems than benefits.

My opinion: I think the ultimate goal of this race is to finish with the Espheni, and thus must use to humans because they have seen that we are stronger than they all expected and they can use us as a "weapon" to defeat the invaders. Therefore, they will  help our guys until they become a nuisance or simply no longer need them. That is, when that big gun is finished. All this can change with the next episode, because as always, we are left with a big question in every episode and theories are just that, theories. Even so, I agree with Weaver, really do not think his intentions are those that claim to be ...
What will happen in tomorrow's episode? Big surprises await us...