nothing wrong with rotating them to get a bit of extra life.. on the daily I normally see the fronts wearing out before the rears, probably very common for fwd cars if you give them some welly on a regular basis, I try to catch them before they get too low and then I can swap them with the rears which more often than not are still pretty much 'new'
it got messed up this time round though because just after I swapped them over I got a rear puncture, so I replaced as a pair, obviously I wanted the newest on the front, so the others got swapped to the back again, a right old faff about
so now in 6 months or so I'll replace the newish old rear ones with new new ones and put them on the front, at which point the old new front ones can go on the back. and if you followed that you can follow anything