They already are I think? With the Persean League iirc, but not sure how much this helps them at the early part of a game because that's where they are the most vulnerable.
They basically have only 1 world (with no starbase at that at the start) and they are immediately up against the Hegemony and the Luddic Church which can at times result in a literal back to back raid, invasion or worse... raid AND invasion from both (sometimes both coming at overlapping time so it's a literal party with 2-3 hostile invasion + raid fleet all massacring the system's meager defenders which cannot pose much of a resistance even with the elite guard HQ)
If they by luck survive this early phase though, they usually can more or less defend themselves reasonably... and if they managed to successfully colonize another place, that usually secure their safety.
If I am playing as the Mayasuran myself, I guarantee their survival by basically rushing to get the hammerhead BC (Mokarran I think?), which is probably still one of the best capital ship that the Mayasuran have due to the combination of high maneuverability (with the system active it literally can turn to face a frigate coming from the rear in seconds and it allows you to move fast enough to stay out of effective range of most other capital ship) and massed frontal facing firepower most of it located right at the front of the ship which gives it a reasonable range advantage (which is absolutely needed to kill the massive number of capital ships that you can end up having to fight) and a battlestation at least on the main planet to help defend it from the numerous fleet coming at it.
In one of my playthrough, with the battlestation and my BC essentially parked next to it, I had to repel 4 invasion + raid fleet almost back to back from Hegemony and Luddic Church, with just enough time gap in between fight and their fleet's travel time (+ they waste time chase after the puny defense fleet) to repair my fleet. Usually by the point the Battlestation is up, and if I have the BC ready in time... I am reasonably confident that no matter how many fleet the Hegemony and Luddic Church throw at the planet... I can fight them off.
