Did you try using the walls or ambushes?

What I do when not using the walls is ambush.

I have a weak and usually weak unit like spearmen stay a bit behind an intersection and when they get attacked I have my much stronger units attack the flanks of the attackers.

I tend to do that ambush more often then not so far because the lag makes defence of the wall take eternity to do, if they fix the lag with a patch though I will just defend the walls.