If you are using a "target the leader" system, then alts wouldnt follow indeed, using a focus based system, they follow just fine as long as you refocus after mounting up.
Before they nerfed the place (or buffed the drakes) i would it easiest to use the 2 red 3 green method from the wiki on this website, also did 5 bronze after getting my macros set up properly (2r3g was easier to set up and needed less practice).
But now, with some gear from heroics, it would probably be easy enough with truly 5 red and no unmounted, and no macros.