The troops are the subject of 攻撃してくる. They're the ones doing the attacking, not the ones who are being pulled into this world.
Obviously the subjects of (引っ張られて)出てくる and 攻撃してくる aren't the same, right?
(edit: Whoops, posted at the same time as Toritoribe-san, again. I'll leave my post here, too, in case the double clarification is helpful.)