[X] With two of the special jounin, they could probably use somebody to watch their backs and they'd be more capable of taking down defenses while you softened up the defenders anyway, probably. It just seems like the best way to get a good fight.
[x] Alone, you operate better that way and, survivors aside, it's probably the stealthiest way to go about something like this. Besides, it's been too long since you weren't part of a team.