I doubt that a militaristic faction dedicated to Gallia being better than everyone would side with Kusari, what Grosh was attempting to say beside the strange hate he was spewing was that the Enclave, or at least his faction as he can't speak for both \*/~ and MdG| is that if they side with the Gallic people they prove the legitimacy of their intentions and have a possibility of swaying public opinion back toward the monarchy and possibly overthrowing the Confederacy. That part makes sense.
My ideal, would be Enclave shooting both factions because they're essentially genocidal maniacs claiming to work for the good of the people, but it's not my faction.
However, the claim about overwhelming kusarians can't really be properly backed as the Enclave playerbase heavily overlaps with the Gallic playerbase, and if it really was ooRP hatred for kusari, they could log Confederacy just fine to outnumber Kusari without needing to log another faction to do so.
as DS said, there is also the part were this war was declared to destroy Gallia's warwolf technology, which only the Enclave is still in possession of, and the part where Kusari claimed to not be after civilians, yet they kind of blew up a civilian depot in Tau-23 and performed a hostile takeover of a civilian base in Tau-53 under the assumption they worked with Enclave, which they do and did. There is a foreign invader in their home that has previously insulted their king on numerous occasions, people with superiority complexes don't typically take kindly to those that insult their holy king on high horse, and would know better than to ally with a nation that didn't like their monarchy, as they'd essentially be choosing between lesser evils, which they were forced to do anyway when siding with the confederacy, because at least the confederates are actually gallic.
I don't fly any of these factions and this war is the type of homo I don't enjoy partaking in, so I'll go back to simping for DS.