So basically, Alith Anar should give upkeep reductions to Shadow Warriors. Even though it's a DLC unit. Just add that as a trait. Super easy and it makes sense. The other thing is that, if you have the DLC with Shadow Warriors, you should get them as a starting unit in mortal empires instead of...an extra spearman unit. Maybe even replace the Eagle unit with them for vortex--but probably not.