I've found the problem. Servidion sent me a copy of the project, they were using saves as a basis for testing, rather than using battle test or starting from 'scratch' after updating. All of which is understandable. They're using a plugin that allows learning of skills in-game, so testing skills in battle test through the Troops tab would have been tedious, and saves would allow them to have everything set up to test things out.
However, and I'm not entirely sure why, the saves retained old data, somehow preventing the states from erasing in battle.
As to why I'm typing this response, I've had moments in game testing where I'd save, make a change, but have to start from scratch gameplay-wise because the changes didn't take. Saves, as far as I can tell, create a snapshot of the game at that point in time, with new and old information coming and going, the older the save, the more glitchy and weird it becomes. So to those of you looking at this topic, if you're relying on saves to do testing, make sure you start a new game every now and again in case something's not working right. The save might be missing information.
I just realised that the reason behind me not being able to make a game may be the lack of my original resources. I just dont like the look of MV faces and sprites, lol. Guess I will have make my own art.
So here's a fun/tragic fact about me: I have an awful memory. But to be correct, I have memory "leaks". My memory is actually amazing, my issue is I can't keep memories for long, in fact, I once forgot my name.