Trow and wights can make an effective pairing if you use them properly. Granted on dark maps the heavy infantry can take out wights like nothing and trow can kick them and barely take a scratch and zerks and myms can easily run away from them. However it seems people just loooooooove to chase trow anywhere they go even up to the banks of a deep river. This is of course where a wight can be used the best. Once you've lead a pack of infantry up to the banks of a river you can bring the wight out and smoke em good. The wight blast doesn't stun the trow at all and of course severly damages the infantry plus stuns them. During the time the infantry is stunned the trow can go nuts kicking the living hell out of everything in sight.

Another way the trow wight combo can be used is to herd enemy units to where you want them. Trow make the perfect wight and artillery guard against infantry because usually the enemy wants to attack wights and artillery with one guy because they don't want to have any other units take damage. Well they can't just use one guy against a trow because the trow can kill it in one kick before it gets anywhere near the wight or artillery. So if the enemy sends an infantry flank north or south on trow if you can get one or two wights and a trow up to the gap you can probably hold it indefinitly against them because they would be too scared of the witghts to move forward.