I think this a good idea. When picking your public March, allow you to pick max number of players. Then if humans can’t fill then fill with bots. Seems easy enough.
As for survivability and lives. Easy, they don’t have a rez timer like humans. They stay dead until a player revives them.
Some issues that would make this difficult. First is pathing and where to go. This would include jumping parts and trap levels. Another one is bot vs player spacing. Prevent them from wandering off or barreling forward in suicide charges. I’m curious if a invisible tether system to keep them close (ish) by.
Why I think this would be fun. One is being in a commander type role, similar to mass effect. Second is the increased difficulty. Sure having a straight option for 1-5man difficulty option for solo runs could be a thing. But a couple extra guns even if they are “lacking” would add to the game play experience.
Of course this is all with my assumption that developing the AI of the bots is not a huge project. I honestly don’t know, I’m just comparing it to other games. And could quite possibly under estimating the undertaking it would take.
In the end, this is still a fantastic game and I appreciate the chance to offer suggestions.