Maybe you should consider adding some unique features to some special maps, especially fortress maps(like Minas Morgul), just like in 3.8.1.
Like in Minas Morgul or Dol Guldor you could recruit corresponding orcs units in ordinary barracks; In Cirith Ungol you could build Cirith Ungol barracks in the settlement ;In Dol Amroth you could recruit Imrahil in fortress and Dol Amroth and other southern soldiers in barracks; In Helms Deep give the Citadel a special ability of giant horns, which could frighten enemy units in the whole map once activated; Give Minas Tirith a beacon in the cliff, which could summon reinforcements from the south Gondor; etc
I think there still exists the bug in Edoras that once Theoden regains consicious he keeps dying(even after recruiting again)
I also think it may be interesting to make Black Gate a "fortress" map, let the mordor faction inside the black gate get orcs reinforcement periodically and add some catapult on the black wall. For now it is very hard for Mordor to fight two other factions in this map.
