For this tactic, free Cyclops are usually used, and they have a speed of 5. As I already described in the thread about Orcs, with one castle and a decent set of artifacts, Cyclops can only attack once, because against an Orc in the late game, an Outcast Unit (OU) is essential for any race. And a single stack of Cyclops will have its morale broken by the entire army in one turn, and it won't have a second turn. A couple of secondary units from the Outcast faction plus Dweller allow you to talk about having over 2000 skeletons after 2.5 months, which is about 3000 (Claw Beast, Blood Beast, Archer) damage to the Cyclops, of which there are 16-17, i.e., approximately 4000 HP. Vampires, taking into account Drain Life, and Liches break the morale, and skeletons finish them off with one shot. If both players have several native castles and no secondary units, the Necropolis player will most likely lose, but this situation with castles is generated only if it's done intentionally. In general, the combination of Outcast and Darkness solves many problems against the Orc. This is especially evident in the example of the Orcish Fortress, but you need to eliminate Logistics.