if you get into fighting with the elves, just use snagas. if there is one thing the elves are absolute crap at is attrition warfare.
my last game as isengard quite recently, i found out the really really hard way that sending your uruk hai to fight the elves is too costly for too little gain. they outrun your heavily armored uruks and if you send the raider uruks they get shot to bits. so i said wub it, and massed 5 armies full of snagas plus some weak ass generals and sent them there. though i still suffered like 3 armies destroyed i managed to decimate at least 6 small elven groups as i moved north to Mithlond.