I could build them right off the bat. Love them, too, actually makes quite a different army than all humans. My first game, I created a spider before anyhting else upon startup of the game. That one spider became pretty powerful, and landing that web is fantastic strategy early on, used to break up groups of melee units or an archer from retreating back every turn. I am a fan of Resoln being built around various spider units if that is the plan.