If he prefers to ED2 option to ED, then he should apply to that one ED and let the second school go. Why get bound to your second choice without hearing from the first ?
Oh, and you don’t need to ED to get in. Lots get in EA/RD depending on the schools. And anecdotally, if they offer merit aid, you would have less chance to get ED bcuz why give $ if you don’t need to.
Just to add on to the previous post.