So at what point of development did you finally say "Ahh, Screw It! Let's make him 'Mr. Sensitive'!!"? Even looking at him now, Eduardo seems like the type who, by looks alone, would scare the hell out of small children at a Chuck E. Cheese's, but then get real sensitive and drown in a pool of his own tears since he'd be crying so much.
Personally, I like the sketch on the far left where Eduardo looks as if he could be the proverbial "Big Bully on Campus", who'd shake down the rest of the occupants of the Foster Estate for ANYTHING that he decided that he wanted at that moment, and the ONLY three people that have the power to keep him in line would be Mr. Herriman, Madame Frieda Foster, and Miss Frances "Frankie" Foster (in that order).