Yeah, it would be nice. But then you have the problem of people just throwing three pendulums in. There are just too many loopholes to make perfect rules that are -also- simple. =/
The only simple way to avoid Immolationbows and speedbows is banning Immolation and Nova. While I could make that change now since it's still Wednesday, I don't like ruining the deckbuilding some people have already done. However, it would certainly force us to be creative, which is awesome. Mm..