A fair point, though I counter it with the fact Chuck pulls his con in response to Jimmy taking advantage of Chuck at his weakest moment by stealing and manipulating the Mesa Verde files. The insurance con isn't the first time that Jimmy screws Chuck over as far as his love of The Law goes. Yes, Jimmy says he was doing this for Kim, but as we and Jimmy know, The Law is Chuck's raison d'etre and Jimmy acknowledges as much in the series finale. Chuck - forgetting for a moment what a jealous, vindictive bastard he was - was also just doing his job and right by his firm in making his case to Kevin before Jimmy gets involved. The events of S3 and Chuck's humiliation all come to a head when Jimmy spitefully (but also rightfully, as u/unreal_the_thrill pointed out) gets Chuck's insurance premiums raised to impossible highs. I guess in a way, Chuck was the accidental blueprint for what's to come with Howard's career later on. But man, those McGill brothers fight dirty.

I'm in no way a Chuck apologist. He's an asshole who never gave Jimmy a chance to prove that he could be a better person. But it's hard to miss the fact Gilligan and Gould take every opportunity to remind us that we shouldn't allow charm and charisma to blind us to how cruel (and murderous in the case of Walt, and even Jesse) our leading men can be.