Couldn't find a way to resolve the conflict of two separate mods doing different stuff to the same file, so I made a single mod that does both things instead of wasting time looking for a work-around.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2838826114

I think I know why it's doing that. Lemme modify the mod, should fix it

So there is one strange conflict this has. I'm using a mod that removes the cap on special unit recruitment, so you can have more than 3 foreign special marines eg. And for some reason it conflicts with this mod and they both cause the other not to work. Narrowed down all the mods and it is only this pairing that have the issue.
Cannons don't fall under capped units that I am aware of, so there shouldn't be any interaction and problems between the mods at all.

Thank you so much for your time and effort