ither you have a really bad framerate or you have a bad connection.
the first would suggest that your system is to low, or your graphics settings are to high.
the second would suggest that your connection isn´t good enough.
test the framerate by playing singleplayer. if you already have problems there you really should lower the graphics settings.
as the others said already, demigod has much higher requirements than wow or wc3.
if its your connection which causes the problems you should be certain that you are not running any down- or uploads in the background and noone else is using the connection while you play.
you can also run a speedtest to check if your connection is good enough: www.speedtest.net
post your results here.
does it lag in a 2vs2 too? or just in 5on5? the more players, the more likely it is to lag.