That is true except for:
tanks, mage, warlock, heal priest, dps war, rogue.
Which leaves:
hunter, shadow priest, retri pala, dps sham.
Mookin and feral dps is neutral.
Since for this expac the dps ranking were like this back in retail:
hunter>rogue>warrior>warlock>mage>sham>pala>druid> spriest
I would say alliance comes out on top overall.
p.s. Before you go silly mode on me...
http://i.imgur.com/y7dxdN7.jpg
hunter top dps ->
ALLIANCE https://www.wowprogress.com/guild/us.../Huge+in+Japan
("Notably, we guild faction changed during MoP, going from Alliance to Horde.")
rogue top dps ->
ALLIANCE https://www.wowprogress.com/guild/us...skull/Deus+Vox
warrior top dps ->
ALLIANCE https://www.wowprogress.com/guild/us...skull/Deus+Vox
warlock top dps ->
ALLIANCE https://www.wowprogress.com/guild/eu...ng/Shenanigans
mage top dps ->
HORDE https://www.wowprogress.com/guild/us.../Elitist+Jerks
(contradicts what i said but lock/mage same racials)
shaman top dps ->
ALLIANCE https://www.wowprogress.com/guild/us...skull/Deus+Vox
(also contradicts no idea why, everyone else was going resto?)
paladin top dps ->
HORDE https://www.wowprogress.com/guild/us/mug-thol/Odyssey
druid top dps ->
ALLIANCE https://www.wowprogress.com/guild/eu/ravencrest/Borked
(druids got the draenei party buff!)
priest top dps ->
ALLIANCE https://www.wowprogress.com/guild/us/area-52/Raze
(contradicts what i said, im not familiar with the race specific spells though, could be it)
"my errors": So you have 1 with mages going to horde.... and 2 with shaman+priest going to alliance.
7 out of 9 classes alliance was top dps, with mage obviously dubious... make your choice.
p.s.2
If you are a pala... Ofc.... By all means. Go horde!
Just noticed hunter guild faction changed, so not even that horde has better. Guess the hit chance for pet > pet damage+ap.