So I've been having a problem for a little while with Legio eating the entire sector for breakfast while I'm busy with other things, Sindia is already long gone and Tri Tach isn't looking too healthy in my save atm. Is there some setting or other I can tweak to make it a bit easier for factions to defend themselves against Legio in particular? So far all other fleets seem to be acting normal in that there seems to be a 50/50 chance that they may or may not conquer whatever planet they're invading, but unless I'm there with my entire fleet of multiple capitals and support craft, the Legio fleets flatten the defenders every time and take over their planet. I've tried simply taking back everything, but tedium aside, this results in Saturation bombardments reducing the colonies to ash, so it's ultimately futile. So is there anything I can do to balance them out a bit other than going planet to planet and taking them out? I'd rather not face that process again. I've been loving the mod otherwise, and really don't want to just turn off LI since they're one of the few factions I take seriously when fighting.
I had a similar issue. My way to deal with it in game was simply to take their toys: go to Lucifron, use an operative to disable the shields, invade, take all the cores and the forge, keep the colony or give it to another faction. Rinse and repeat for the entire system. After that, Legio just crumbled and never recovered. It is extremely tedious though (it does give you some nice loot for your trouble).
Caveat: it may be already too late in your game (especially if they already have several massive markets with pristine nanoforge).
but I only learned about the fleets thing a few days ago lol it's been kinda handy for guarding things while they get their defenses back up, but I've it used it for anything else yet. I've just been doing everything myself until now