[kamrann]

I agree with you, I think calling is best. There really isn't much of a downside to it relative to pushing.
When you say you are auto-allin on the flop anyway, would you push on the flop if you miss? Of course you're not folding on the flop or at any point, but since you're hoping to get UTG to come along preflop to help beat the short stack, wouldn't it make more sense to allow him to stay in on the flop also? Sure it's highly unlikely he'll fold on the flop for 600 or so anyway, but just in case shorty has a pair and UTG has called with something like QJ, I'd think it's better to keep him in to maximise the chances of one of you hitting something on turn/river.