So basically...I think this could potentially be a really fun and interesting way of doing "alien variations" without necessarily having them all as separate units.

Alien variant specialisations/proficiencies! Akin to how the SPARKS class mod works:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2674677738

So imagine this. Once you get a Codex or a Black Ice Codex for example, you get it as a "base codex unit" that can be "promoted" to...a normal Codex or a Black Ice Codex with all of its abilities in either class, effectively making the "alien version" its own version and your version a special one that MUST be "assigned" a class (normal or black Ice) before it can be used, just like the Spark Proficiency Mod I've linked

This could also apply to all the different Muton, Viper, Berserker, Sectoid, Archon, Andromedon, Faceless, Chryssallid (maybe not?) variants etc here on the workshop. (Possibly excluding super variants like the Omega Berserker, Ruler & Leader Alien Variants, Muton Harriers/Berleagers and Robotic alien units as well as alien Mecs, best to leave them as there own units).

I think that could be awesome, however I realise it could also be A TON more work than just simply getting the alien as a unit you can capture/make/use/recruit like Playable Aliens/Rulers etc.

I'd like to look into the feasibility of this idea, it would certainly be nice to use for Vipers and Mutons at least as there are so many variations of them.