Adding decisions and changing unit types mid campaign

[Changeling_Wil]

So, is it possible?

I've been trying to add imitation legionaries to Bacteria, but when I load the save after making the edits to factions.csv, it crashes.

So I've been thinking about making a decision so that when you say, take Babylon, some Seleucid units are added to your roaster. Would such a thing be possible to do, or do I desire something impossible for this current campaign?

It's no worries either way, it just seemed a tad strange that despite replacing the Seleucids I was still largely stuck with my original roster, bar provincial units.