It works with Stampede though. All you have to do is the first pet you summon to be the "leader", and have it under your control. The following pets will then be the, well, "followers", and assume the pet assist function, attacking whatever the first pet attacks. Simple. Once the leader dies, the "second in line" will take the leader role.
As for abilities: Damage attacks do not need to be on the bar and Empower and Reinforce could be merged. Assuming both PE and SET, we'd have in our pet bar, assuming all three would be active at the very same time: Harden Skin, Pulverize, Reinforce, and Gale Winds
Eye of the Storm is an passive effect, so no need of putting that in the bar either. Four skill should fit in a pet bar no problem. A problem might be Call Lightning though, as it is a casted spell and PE SET giving that speed aura would make us want them not to cast it while chasing someone, as we would lose the aura...would five spells fit into a pet bar?