Well, I just posted my next action, so I am hoping that:
1) Uth-gar fails his reflex save and takes the full 16 hp of damage
2) The other 3 hobbies fail as well and die from 16 hp damage.
That would leave us the Uth-Gar, invisible cleric, and 2 hobbies to deal with.
I think next round I am hitting Uth-gar with empowered ray of enfeeblement to reduce his damage.. he is slicing and dicing like a cuisinart. Hopefully Durion can land one or two sneak attack blows this round to further soften him up.
I'd recommend getting more hp back into Jonathan this round. He is most likely going to take one or two hits from getting back up.
Don't forget Durion's +1 to hit vs. Goblinoids -- not sure if you have that added in with your flanking bonuses....