I think thats one of the many awesome aspects of the songs and its something IM haven't done. Really makes the song stick out and adds power to Bruce's vocals. That song is a BEAST and although it kind of is like your standard Steve Harris IM epic, it really feels like its one of the better ones IMO. Granted it is also new so maybe over time my opinion will change.
It's not really a new thing for Maiden; Steve did the same thing on the last album with When the Wild Wind Blows. It just felt more natural/less noticeable there because the main melody was more nursery rhyme-ish. Also, while Bruce does sing really high on the main melody for TRatB, he sounds strained a lot of the time to me. I'm hesitant to imagine him singing this song consistently on the tour next year.
As for where this song ranks among Steve's IM epics... honestly, I think this one's the weakest he's done in a long time. At least since No More Tears and possibly even longer than that. It's not as lyrically repetitive as a lot of his stuff from the late 80's onward, but I just get the impression that Steve sat down one afternoon in the studio, came up with a bunch of riffs and strung 'em together and said, "Eh, that should do." It comes off like an incomplete homework essay that was rushed at the last second. Something that
could have been absolutely incredible, had Steve just taken more time to work things out.
I think that's the result of how this album was written mostly in the studio spontaneously (IESF, SoL and DoG were all written in advance though). I think the new approach worked
brilliantly, as the band sounds incredibly inspired on this album, but I think Steve himself probably works better when he's given a bit more time to tinker around with his own work.