Some people seem to tihnk Guard is too powerful. One slight nerf might be to say that a player could only use before he takes his action in a turn. Once he has moved he becomes too involved in what he is doing to help out his mates. This makes the skill feel more like its name in that there would be some real "guarding" going on. Plus it becomes slightly more tactical in its use, and might slow down the rolling walls of four of five players with Guard (which is really what people are complaining about isn't it?).
Cheers

Joe
*This post may have been made without the use of a hat.