I've never really though of AI having strategy. They always seem to periodically tank rush. If you've looked at an RA1 ini file, the default setting is to attack 10 minutes into the skirmish, and then every five minutes therafter. They would use helicopters, but never Yaks, MiGs, or any naval unit. They're base would consist of CY, 1 barracks, 1 WF, 1 Radar, 6 or 7 Refineries, 4 or 5 helipads, and seemingly enough power to somehow keep it all running. In RA1 skirmishes, Sub Pens/NYs, Tech Centres, Chronospheres, A-Bomb Silos, and Airfields were never built. At least, not by the AI.
RA2 was an improvement, Medium/Brutal Soviets will use Subs, but for the most part they would rely on 1 or 3 kirovs to kill you, if their Engineer rush at the start failed.
I can't remember TS much, but I don't rmeember being impresed.