I definitely vote for the first one you posted - the positions look much more natural for all three of them than in these last two.
The policeman does look suspiciously close to making a pass at the soldier in #2
As far as the fireman being tall, maybe you could just shorten him a little bit, so that he's not a full head taller than the other guys, but still taller than the soldier? I like that he's taller - maybe just lessen the scale of the height difference.
Hybrid Mode
