I was looking at Alkyoneus and trying to figure out how much damage my heroes would take every five rounds and the like, and the thing that confused me the most was the basic attacks.

How does Basic attack damage get assigned? As in, if I, hypothetically, had six heroes.

AD

BE

CF

where A,B, and C are in the back row, who takes damage from a basic attack? Is it always E? If that's the case, if E dies, is it D or F? If the damage is split among the front row, is it a 33-33-33 split, or does the center take more damage?

Sorry if this is a stupid question, but I could not find any information about how the rows work in any of the pinned material.