So today I discovered something after I merged a sor account into my own.
I had some faction specific mounts on my ally characters like the chopper and the travelers tundra mammoth but refused to by them on my horde characters. I did the sor on the account and when i logged in it got my mounts even tho it was a different account under my battle.net. I knew that would happen However I did not know that when i used the free faction change on it that after the faction change I would also get the horde ones as well. This char did not own those mounts and afterward on my main account i had the horde versions as well. I know that to get those you are supposed to faction change the specific character. However doing it this way worked I believe because it was on a separate account.
So heres exactly what i did.
SOR the character and did the server change.
DO NOT DO THE FACTION CHANGE IMMEDIATELY
login to get the same faction mounts. (ally for example)
then do the free faction change. (to horde for example)
login and get your new free mounts. (as your new horde)
login to your old characters to the SOR chars new faction to get the new faction specific mounts. (your old horde characters different account under same bnet.)