I just finished leveling 3mage+priest with a level 60 mage.
I leveled in starting area till 8
8-12 rfc
12-25 in sfk
25-30 in SM
30-50 maraudon
50-60 brd gorshak.

I did it as a group of 4+1Powerleveler, you could cycle out the highest level PLee every 2 or so levels and bring in ur 5th if you need to powerlevel 5.