yes that one...Acheron has the Magic Immune promotion, so it makes sense Command wouldn't work. As for the Sons of Asena, would the Loyalty promotion block Command? I can't recall.
"New random seed on reload"
are you sure "command" is supposed to be counted as magical effect ? it's not the Mind3 spell. (I don't see why it shouldn't work like the subdue beast/animal promotion, but with %chances) But you might be right, I don't really know the c++ that is hidden behind the xml.
Loyalty is supposed to block being overtaken by command (and domination, and even subdue animal/beast). I forgot that those guys might have that promotion.