Skills for an Inferno hero.

Chaos Magic, Summoning Magic, Logistics, Leadership, Luck, Gate Opening.
All together – an unbeatable power.

I don't know about Summoning, but I agree with the rest.

Added 3 minutes later
Yes, by the way! If the focus is on the number of troops, you can have some fun with Hellfire. Naturally, with its enhancements – Fiery Retribution (defense) and Blazing Inferno (chaos).