I think this game is moving more toward the static camp as before. Here's why: Mages regain MP at a much faster rate when standing still; Movement will cancel casting; If you are in a Stronghold party without 50's to carry you, there is little need to roam as the respawn rate is so short; Mob concentration is very dense in many places; Many of the AoE Weaponskills are gone.
Exorcism Beans, Chakrams, Throwing Daggers.. all of those have a significantly less range to them compared to that of Archer and what I will assume will carry over into the Bowharp's range. Regarding Swiftsong, I imagine the sequence of pulling might go something like this: Utsusemi/Swiftsong > Buff group > Pull 4-5 mobs > Sleep > PLD Flash the group > PLD /ra 1 mob for the group > Group Defeats the mob > PLD pulls next /ra (Until group reduced to last) > Repeat.
As far as leashing, there are many spots where a group can stand and still pull from 2 or more immediate areas without having the mobs return. Just as in XI, there were key spots to camp in a group of target mobs - same here.
Thank you for not defaulting me as a troll and giving honest feedback to my suggestion.
EDIT: The only demerits anyone gave anything in this entire thread was to FFXI, Ninja and how Utsusemi was implemented and sometimes abused in that game. Trust me, not one person gave a single shred of commentary as to why it would or would not work in this game as I have suggested.