Actually it's how classes are made - dodgers dodge, bc crit, heavyweights block. When you're a mage you still have your class stats which are supposed to work. But weavyweights and bc dodge pretty often, and dodgers block, which is weird. But why does it happens? Because upgraded runes don't increase your class stats only (like str and agi for dodgers), they give you stats of other two classes too, which you don't really need. For example my
Rune of Lightning B'yal V gave me +4 protection, and sometimes I block, my I'm not a heavyweight, I'm supposed to dodge not block. Same with upgraded runes for other classes.
That's why bc dodge. Especially, I think, on mage levels where you get more stats from upraded runes.