Rookies Begone! Trying to make a mod that controls what classes you have access to.

The idea, in my head, is simple, the execution is... I had no idea if this is even reasonably feasible, and so I find myself here.

I just cleared my first War of the Chosen run, and I was thinking about how, in a lot of ways, the "Hero" classes are strong, and interesting, but not capable of really quite filling the same roles as the "classic" classes, so I thought... What if I reversed the accessibility? What if I had a lot of "Hero" classes, but limited access to more classic roles?

The only way I could figure out how to, reasonably, manage that would be to go to the ship's recruitment, that usually lets you hire tons 'o rookies and replace them with... Not rookies, instead specific classes. If I could do that and weight it towards specific classes (IE: Aforementioned dearth of classic classes, but plenty of heroes) then I could force myself to try to come up with unusual strategies since my more common tool set would be of more limited access.

This is especially true as, without Rookies, I couldn't just use the GTS to produce whatever I wanted, instead just having to deal with the cards I'm dealt, as it were, outside of maybe Rookies as scan/operation rewards (I know I can finaggle that, at least).

But I've spent some time searching around and I have no idea if it's even reasonably possible to do, or maybe it'd be completely easy to do with a little .ini manipulation, I just haven't been able to figure it out myself.

I suppose this is half Mod request, half just looking for technical info. I'm more than happy to do the work myself, as it were, but I don't know where to even start, so any help would be much appreciated!

Thanks for your time.