Like BarretOblivion said it becomes a lot of stress on healers. I actually think you wouldn't have enough oGCD heals for it, so it make them resort to GCD heals - which you actually want to avoid.

Imho it's more effective if you can use hallowed ground on it, and invul fae light healed by bene (or vice versa). Or you play with 2 WHM and bene both invuls if you don't have a PLD. If you don't have any WHM or PLD, it would be better for everyone to take a tether. You can heal that with earthly star, indomitability, fey blessing, whispering dawn, consolation, sacred soil hot, collective, opposition... (that's all I think) after the tether resolved. You'd have to heal the remaing 3 other after the tank anyway, so I don't see the reason to bust your resources on one target - unless you wouldn't use them anyway.