Herd of what?
My question is why
Cavalcade of Calamity? I see a total of five creatures that could benefit from it and of those the Warleader tokens would need to be surviving a round to trigger CoC.
Ignite the Beacon is really overkill with just one planeswalker to find when you could find two. Looking at similar effects Call of the Gatewatch will find one, admittedly at sorcery speed, for just 3 mana while
Djeru, With Eyes Open is a five mana legendary creature that would also do the same thing. Maybe you've got the Beacons but to keep them I might try to find more planeswalkers as they are overkill for one and may be dead cards when drawn after the planeswalker.