No. B580 will not be the highest-end on Battlemage, but will be the replacement of the A580, which was part of the middle of the ground Arc 5 lineup.
Top of the line should be in the Arc 7 lineup, so B770 and B750 cards. And of course the low end should be the likes of Arc 3 B380 etc.
Yeah that is correct,this journalism is not that good.