1 Ursamajor will be spawned at the beginning of the battle, along with a wave of peons.
4 Ursamajor will be spawned as bosses once you damage the base. However, a player can use the fact that they can be knocked back behind the enemy base advantageously. Ururun, Bahamut, Crazed Gross, Macho Legs, and both King and Crazed Dragons are fantastic.
Still not hard in 4 stars. Just use ranged units that outrange Ursamajor and some meatshields. This stage is definitely the easiest one of this sub-chapter, even in 4 star