I can't stand the rock, paper, scissors style units either. Have a look at Panzer General 2 and related SSI games. The units are very variable in strength and terrain is a factor in battles. Do that in an RTS and it may hook me in.
Although you don't have to bother with single player in the networking age if you do... Have the AI mass armies instead of just sending out little skirmish forces at regular intervals.
Have a good story joining your campaign together.
