Yeah, I've noticed that the AI likes its Riots, often to the exclusion of other things.
I remember a while back where they changed the code to have a proportional number of starships for each wave, as opposed to a single starship and a crapload of ships. I think that the special forces are gaming the system by just buying starships, since it seems to get a little more leeway in what's assigned.
On a side note, Riots plus hydras in the special forces is a whole new kind of infuriating. Might as well just throw your fleet away.