I am currently farming rep. to get this achievement but I am not even rushing it - I started this in MoP, stopped in WoD and get to it again during Legion.

Honored with Bloodsail Buccaneers => done
Exalted with Ratchet
Exalted with Booty Bay
Exalted with Gadgetzan
Exalted with Everlook
Exalted with Darkmoon Faire => done
Exalted with Ravenholdt => done

So, as you all can see I am just missing the Goblin reps. - i did them before I farmed the Bloodsail and now I have to re-get them to exalted.
That being said, once in a while I will be openning groups so people can join in to farm these reputations.
Farm spot: Tanaris just behind Caverns of Time, by the beach & on/in the ships.

However if anyone wanna to share some BNet tags to coordinate a bit better, let me know in here.
Btw, I am farming these reps. on this Protadin and I play on a PvE server.

Best regards, Sig!