[K]

I've had some success with the idea. The key is not to put them not on crap indie commanders, but commanders with high natural precision. Toss in an Eye of Aiming and you can be firing a seriously devastating volley with a Bow of War (gets even better with Flaming Arrows). Bows of War are also a natural source of very good archery for nations that don't do it at all.

The other bows also have situational uses, and in general the "items army" can use the gems better with items that don't run out of ammo. My personal favorite is using four guys with Rods of the Phoenix and boots of Quickening and some basic Reinvig.