Tiered strongholds could provide opportunities to learning combat methods, interact with crafting side quests, and earning loot for NPC engagements. The goal is to take out the stronghold as fast as possible while completing required objective(s) for capture points. Learning combat methods
Each stronghold could have varying number of guards and ranks for training combat methods.
Outposts could have 5 guards.
Towers could have 3 guards + 1 captain.
Forts could have 10 guards + 1 captain + 1 lieutenant.
Keeps could have 25 guards + 2 captains + 1 lieutenant + 1 commander.
"Walking" higher-ranked general in the surrounding area could be rallied against attacks in a zone.
Fort general could be called when capturing starts to occur.
Keep general could be called when tree of life is under attack.
Interact with crafting side quests
Each stronghold could have varying number of quests for dropping crafting recipes.
Common recipes would still be available from specific disciplines.
Outposts could have food recipes because this one guard makes uncommon <item>.
Towers could have weapon recipes because the captain has a rare <item>.
Forts could have armor recipes because the lieutenant has an epic <item>.
Keeps could have jewelry recipes because the commander has an legendary <item>.
Introduce different racial NPC's for harvesting body parts after successful attacks.
Trials could have different races for all strongholds.
Each zone could have different races for the strongholds during a trial.
Earning loot for NPC engagements
Each stronghold could have varying number of loot for NPC groups.
Outposts could have gold cache.
Towers could have leather/ore/stone cache.
Forts could have dust caches.
Keeps could have chaos ember caches.
Introduce different rarity drops according to the seasons.
Spring could have 4x.
Summer could have 3x.
Fall could have 2x.
Winter could have 1x.