A few panels before that, Chester comments that the scheme will be a great gag on the Bigbucks store. This suggests that he's involved with this for the fun of it, and assumes in his naivete that Mad Doctor Doom is too. In subsequent stories featuring the two of them, that I recall at least, Chester comes across more as a typical "greaser" teenager, into girls, hot rods and maintaining his pompadour; unllike his boss, he isn't a "muahaha evil" sort.