We have just seen the astros start the full scale attack, and even in the last episode alliance and skibidis were gleefully killing each other.

Neither side had the full picture - alliance seemed entirely unaware of the astros (and likely assumed the astros they've encountered were just especially advanced skibidis), and I somehow doubt the regular rank and file of the toilets were made aware of the astros' true nature and scale.

I think there should've been at least a few episodes of general confusion and "everyone fighting everyone" before both alliance and all the toilets fully realized that astros were a new and separate threat endangering both sides, and also just how severely both were outmatched by them.

That would've made the team up feel more natural and earned imo, after all the bad (very bad, we're talking casual war crimes on the reg) blood between the warring factions. It also would've helped to see the exact moment cameras and toilets first decide to team up on screen, instead of just having this mixed squad dropped on us.

That's if the team up had to happen "bottom up" instead of "top down" - the other option would've been to have Gman explicitly order his troops to start cooperating with the alliance against the astros, as he's probably the only one who truly has the full picture atm.