As Roopy said, we may see a different side on the weekend anyway so he may just be covering his bases. I have a feeling though that if nothing happens injury-wise, he'll just use this side anyway.
Nowadays we consider Cooper, Brown and Lowrie to be utility players so it is a bit strange that we see them all named, especially considering it's not an 18- or 19-man team we'd expect to see if some are under a cloud. I guess that on a good day this bench would be able to do the job very well, and if we've got good momentum they'd most probably carve it up if the plan is to dominate in the forwards from the start then move the ball around; I don't think that Souths could handle that too well. But I would feel much more comfortable if Brown were to be swapped for another forward anyway. Brown had indeed been playing very well in PL, but Hagan might have chosen the wrong circumstances and timing in which to reward him, as strange as that may sound. Time will tell.