all you really need to implement iron valiant is enough switching cards. we saw this with last tormat, as iron valiant decks basically took the entei v rogue deck and implemented itself into it seemlessly to become a viable deck. we're not using iron valiant to attack, mainly to use its damage support
Entei only has a 2 energy requirement and magma basin was a stadium that helped accelerate energies. This allowed the use of sqwak and professor's research to cycle through switch cards.
Brute bonnet needs 3 darkness energies to attack. Powering up this thing is realistically only possible with sada's vitality and dark patches. You now don't have enough draw power to cycle switch cards.