How do I remove a Faction (specifically, the Stronghold) from the available options entirely?

Yeah, orcs are like that... I also thought that WIZARDS with the RoC were the best – any magic, cool creatures... until I played a battle with equal compositions against orcs.... Orcs simply crushed me without a chance, despite all my magic.... and I could beat anyone with mages, without any particular problems... that's how it is....