Maybe, but its simply not working as described currently. Should either fix or re-balance. IMO making it worked as described (a very strong power buff to sniping elites while you are dealing with a horde) is the most interesting, and fits with the class. If that means it should be nerfed to something like 5% per stack/7 stack cap, then so be it.
As a general thing, I don’t see how WPoS getting +40% power on a Heavy by doing a light first is all that must stronger than a Zealot getting +30% on both attacks, along with any other attack combination he does as well, whether he’s fighting a horde or not.
15% crit chance assumes you kill 3 elites at the beginning of battle and then continue to kill another every 12s. Bit of a shaky thing to base your strategy on. If it was 20s then I’d consider it a lot better. As it is you kind of have to beg your ranged characters not to kill elites a lot of the time as a melee career, and even in melee whether you get a killing blow on elites is highly up to chance.
A small buff to them to make it more universally interesting isn’t going to imbalance the class.
In particular the problem with stagger power is that because it’s a 100% binary condition there is a good chance it literally does nothing for the rest of the team. And is anyone actually going to bring up an excel spreadsheet upon joining the game and seeing that WPoS has +stagger aura equipped (after Fatshark fixes the game to let us see skills)?