So, maybe I just screwed up here, but pretty sure I didn't.

I promoted two of my position coaches to OC and DC thinking it would just fire my current OC and DC. It did and then rehired them as the position coaches and they are getting paid more than the two I promoted. It's entirely possible I made them the offers, but I didn't think I did.

It tells me I need to fix this, but I can't because they all just signed contracts.

Did it happen on a game stage? When you enter a game stage without coaches (which will happen when you promote a position coach to coordinator) the AI will sign coaches to fill all positions. There is a bug also where the AI doesn't correctly follow the coach salary hierarchy, so sometimes when that happens you'll get the coach salary imbalance error message. You can either replace those two coaches, or if you want to keep them, you can rebalance your coach salaries (it will keep the same total coach salary amount but distribute it so your coordinators make twice what your position coaches make, and your head coach will make twice what your coordinators make).

Ok. I'll just replace them. Thought I had made offers for those positions the same time I promoted those position coaches though.