I don’t know if this idea has been discussed, as I haven’t seen it, but here’s the concept:
We have PvP servers where players attack/raid other players & buildings are vulnerable.
We have PvE-C servers where players attack each other & buildings can be raided, but are invulnerable.
And we have PvE servers where players cannot attack/raid each other (except in creative, monster-luring ways) and buildings are invulnerable (except to said monsters).
So what about players gathering thralls to send to attack a player’s base? The thralls are the combatants (like a manual Purge). On PvP players may accompany the Thrall army and destroy another player’s base. On PvE-C, players may accompany the Thrall army, but the player cannot destroy the player’s base (but perhaps Thralls could). On PvE, players may accompany the Thrall army, but the player cannot destroy the enemy player or base (though perhaps Thralls could). The specific mechanics and balancing I would leave up to the devs to work out; the basic idea is using Thralls for more than defense, but rather for offense.
Perhaps a Barracks workstation to assign a number of Thralls (say eight per Squad) to a specific unit. That unit could be commanded by the player (perhaps even multiple units of Thralls). Thus, players could not only be kings of building bases, but perhaps of Thrall armies as well (attacking and raiding to their heart’s content).
Of course, to make this work, players would need some controls for giving general orders to the fielded units (attack a specific point, defend a location [like a treb], ignore peaceful wildlife, etc.). And to make things very interesting, it might be fun to just send out a squad of thralls on a patrol path to kill anything it finds (with established waypoints) where the player doesn’t even have to be present (letting the player call up a set of pre-established, player-made waypoint blueprints to choose from [with a maximum number that can be kept on file] – to send out a squad on patrol – even into a distant biome clear across the map). One might target a known player’s base at a set of coordinates or another might send a patrol out to march around the Summoning Place and then return home. I hope this idea (or others like it) would see more Thrall use (and increased fun).