While Vibe's idea is not bad in general, I fear the effect won't be
It might even add to depth that you'll use different stances versus different builds and could get pretty complicated
rather the opposite, the different builds will feel even more the same. I think people will rather tend to neutralize their weaknesses instead of further improving the advantages they already have.
With such a change you would make the extreme builds even more extreme, but on the other hand, people wouldn't have great weaknesses any more.
The idea to have the possibility to take a wide swing before smashing someone's skull from behind seems appealing to me, but it works against the system of the "STR-AGI-competition" and iteam requirements/stats.
Single builds being more flexible means more allrounders and less dependancy on teammates, which can't contribute to the gameplay on the servers.
But, as you can see, it's just my personal opinion, because I value the quality of teamplay higher than the possibilities for single players, even if they require skill. That's why I stay neutral to this suggestion.