Star Trek

I would expect Xindi strong Earth allies after Zero hour not basic dispeared of screen.  While Enterpise Board land we they did not talk what other major powers going do if Klingon attack. But being Romulus and Earth wars we did not see single Xindi starship aid in conflict. My question is why?

Regardless of what the Primates, Arboreals, and Aquatics did, I suspect that formal relations between the two factions would be impossible for a very long time, since a large number of humans were understandably suspicious of them (as seen in "Home", "Demons", and "Terra Prime".

They had internal problems, and needed to deal with them.  The Primates, Arboreals & Aquatics were probably all on good terms with each other, but the Insectoids & Reptilians had gone off to launch the weapon together.  After the Insectoids figured out that the Guardians used the anomolies to protect the weapon & realized they were likely the Sphere Builders as Archer had said, and the Reptilians destroyed the Insectoid ship, those 2 were probably in conflict.  With the Delphic Expanse returning to normal space, they were also probably uite busy figuring out what to do about a new homeworld.