Well its just first to start to beat the hardest computers on single player then you will have some kind of tactic and priority of buildings and soldiers and then at multiplayer some one will kick your ass.
Atleast this was my exp. at warhammer 40k before time when I was playing it regulary with a friend.
But in the end its geting boring making only one or 2 tactics wich are the only way to win, dont think that there is much flexibility at the hardest computers and ppl. (maybe Im misstaken, as I havent played online strategies for a long time (but this is other sad stroy) =( )