Hulk can take Firelord and Strange can occupy Norrin with Namor an x-factor (he may well go down early to Firelord but be back in the fight later to help out).
Heralds can win if Firelord drops Namor early and Surfer goes straight for an energy drain on Hulk, but I think if push came to shove Strange could likely counter those kind of attacks to some extent.
To be honest, I think the days of anyone being able to drain Hulk are way over. He is an open conduit, and if Surfer CAN drain him down, Hulk just re-amps the second Surfer stops. For Surfer to keep Hulk out of the fight he'd have to spend all his focus on Hulk the entire time. This leaves Fire Lord to deal with Strange and Namor alone... I don't see the Heralds pulling a win here.