I'd take both of them over Karl personally. Big on postseason performances and those two consistently rose to a level that Malone did not as an offensive anchor. Would be willing to overlook his offensive shortcomings by comparison if he were a dominant defender like KG who wasn't a consistent takeover scorer himself, but that isn't the case. If you want to talk all time rather than prime though I can see strong reason for Karl over Chuck given the longevity
This Karl Malone postseason stuff is mostly a legend. He often played at a high level there, but I'd agree that Barkley and mainly Dirk played at a higher level as well. I'd take Karl over Barkley for several reasons: he was a better defender (he wasn't that great but still above Chuck), more consistent, more durable, had better work ethic and a better scorer. He also went to the postseas in every season of his career. Chuck was better as a rebounder, was a good playoff performer but I'd still take Malone over him.