Or instead of making silly limitations for gear they could remove stamina from PvE gear, balancing encounters around dpsers and healers not having that much health and more of other stats to compensate. This will make PvP gear useless in PvE as the large amount of the item budget spent on stamina is wasted, and will really make people in PvP wearing PvE gear much more squishy.
I think this would become problematic with pom/pyro mages and eleshamans, particularly in 2s, where they could instagib one person then LoS while their partner fought. Or, if they died, so long as they dropped someone, they could just team up with a good 1v1 class and just let their partner go to town.
I've considered ideas like this, but it just doesn't seem practical. Hell, look at T6 shstep rogues. Imagine that, but several times stronger, with a 41 yard range, and ice block.