So in pve, the more players there are in an encounter, the bigger it scales to them. So what if camps, towers and keeps do the same. The bigger the zerg, the more effort it will take to break down a gate or a wall. And for camps, more Elites can spawn?!
I think upgrades would be the way to go about this. So maybe once all walls and gates in a Tower and a Keep are fully upgraded, you get a final upgrade that lets you detect how many players are around the area. It would have a 360 radius, with a decent size, not too big, but definitely not small, so just in case a zerg is hiding behind in a corner, it would detect them still.
For Stonemist Castle, since it has so many walls and gates, the detection area would remain within a specific gate or wall that a zerg is in, so e.g. if a zerg is pounding on one gate, then that gate only gets scaled, and not all of SM. And this could be true for other structures too.
So maybe this could encourage more smaller group play.
I just thought of this just now, so it’s not fleshed out obviously, but throwing it out there anyways.
“I got a fever! And the only prescription, is more COWBELL!”