Here's the skill combination that Raillag has during this mission. His main strength lies in the Meteor Shower and Ring of Cold spells, enhanced with various upgrades. Notably, he received the Logistics skill almost immediately, which is very helpful. And of course, Sorcery, as expected.

P.S. There was a lot of talk about buying out enemy heroes. Yes, that's definitely a viable strategy. But there's a limit to how many heroes you can have; I'm not sure exactly how many, but it seems like a player can only have 7 or 8 heroes at a time. And right now, my heroes have already defeated 5 of their strong heroes. How many strong heroes do the blue players have in total?