adding courage of the colossus, sure. but strength of the ages is really not an issue and an overall pretty balanced mastery. there is enough room in the tree for 4 keystones.
granted, i still think the 5% heal is totally useless by the time you get it, and i still think it could use some adjustments to be more useful for laners. but the mastery is not overpowered (fervor? where is the nerf to that?).
and honestly, if a mastery was replaced by a full defensive mastery, i was actually expecting it to be grasp.