I'm not saying that all of them would be player controlled from the start (nor would they be aggressive from the start, either), just have them be the actual ones rather than the simpler versions, that's all I ask. Right now, it's dull, while it could be awesome.
Keep in mind that player controlled xenobiology creatures would actually only be able to start outbreaks if the owner is a traitor, which doesn't happen often.
Any creature created through a xenobiology player controlled creature would count as owned by the xenobiologist, so they wouldn't do anything either.
IF a xenobiologist had made some player controlled xenos / terror spiders earlier and an actual outbreak happens as a random event, then the player controlled creatures would break out of their "debt" and give the outbreak a small headstart, turning against their creators.
It would add a lot of danger and actual important to xenobiology. As it stands, I see way too many xenobiologists make lots of mobs through gold slimes, sometimes even letting them roam outside the cells, too.
Also, with this, I'd suggest giving the other creatures (mega space carps, panthers, space bears, normal spiders, ect) an overhaul as well for when they're player controlled. This is mostly for those abilities that are observed being done by their AI counterparts (like making webs, crawling through vents, ect) that can't be done once you start controlling them. They should also be able to regenerate health overtime.
I know this would take a lot of work and time to add, but it would definitely be worth it, in my opinion.