Stability in its current state is an issue. The issue spans from a few things, so lets address them one by one;
The first issue with Stability, which applies to boons in general in WvW (and the rest of the game) is there is currently way too many. This is an issue from a balance stand point, but the current direction of balance seems to be to up the number of boon strips. I don’t think this is a good direction to take WvW in, as with increased/more frequent boon strips we see stale fights where people refuse to push for fear of stability being corrupted/removed – causing them to effectively instantly die. An ideal fix for this would be to tone down the number of boons applied from skills and passively – causing there to be no need to further increase boon strips; however since that is a far fetched hope a ‘quick fix’ for WvW would be to alter the boon strip mechanics in WvW, to where instead of boon stripping all of a person’s stability stacks it strips 3. This means that even with the current boon strip creep we seem to be seeing people will not be afraid to push – as they do not have to worry about their stability being instantly gone (and them dying).
A secondary issue, which almost directly ties into the first, is the random nature of boon strips. The random nature of boon strips is a change I feel neutral about everywhere except WvW, where it causes issues like this https://www.youtube.com/watch?v=4wEzocIAiqo . The feeling of popping a skill to have it instantly negated with you literally having 0 counter play is not a good one, especially when that skill is essential to being able to push in WvW – the crux of the overarching meta. We have seen the consequences of not being able to push before, with the ‘pirateship meta’ buzzword that people use. This was one of the most boring times to play WvW, with neither side wanting to push for fear of instant death. The fix for this point could take many forms; you could re-implement a partial boon strip order, with stability late in the priority list, you could implement a full blown boon strip order which is uniform for every boon strip skill (something that has never been in the game), you could give stability a ‘grace period’ where it can’t be corrupted (~1.5-2 seconds would feel good). You could make these changes affect all the gamemodes, or just WvW.
Personally I think stability as a mechanic needs an overhaul. The direction I would take with this is a ‘breakbar’ style approach. Each stability granting/stun breaking skill increases your breakbar by a % – up to a cap of 100% and each hard CC takes from the breakbar (with a cooldown on how quickly CC can affect it, much like the current 0.75 ICD). When your breakbar hit 0 no explicit stun or daze effect happens – but instead you become vulnerable to hard CC (i.e a knockback or pull would now work on you). The breakbar would have a steady degeneration to it, and all soft CC (chill, cripple, immob etc) would still function as normal (with the exception of fear, which would affect the breakbar and could only be applied once the bar is broken). I would show a small blue bar under the health bars on the party and squad UI to show the breakbars to the rest of the group. This gives you a visual representation of if you can make a push or not, it allows other group members to see if they should use ‘breakbar filling skills’ on you and it allows the enemy an easier to read visual prompt on if they should CC you. This removes the whole “boon strip” issue from Stability entirely, as it moves Stability of the boon bar and into a game mechanic.
That ZBs guild I mentioned earlier were epic, they had about 45 also and because they were incredibly organised they could achieve anything, with a group of about 20 you can have some nice fights, but you can’t exactly dominate a battlefield.