Ace's experiment number - 262 - is the opposite of Stitch's - 626. Ace is a pure-good-with-no-evil experiment, and Stitch *was* a pure-evil-with-no-good experiment.
According to conceptual storyboards made by Sahin Ersöz, "Ace" was originally going to be more substantial than a clip show. Originally, Jumba would also take the head of E.G.O. around Kokaua Town with Lilo, Stitch, and some of the other experiments staging "evil" incidents to impress him. However, Ace would have ruined their plans by saving the victims. These incidents included Cannonball creating a tidal wave that Pleakley would have played a victim in, only for him to become an actual victim when Ace attempts to rescue Pleakley and several dummies used in the act, forcing Stitch to capture the experiment, which results in Pleakley getting buried by a pile of the dummies in the wave's path. Jumba would have saved Pleakley from the wave, which, in turn, would have him kicked out of E.G.O. as a result.