Simon's calling card is talking fast. Campbell likes to slow down his sentences to a trickle and offer these truly dreadful, cliched takes.
Neither of them can ad lib. This is where someone with intelligence, preparedness and the ability to relate to an audience generates interest.
Also, Campbell is annoyingly always on air, for literally anything. At some point, the station ought to get the message and limit him. His play by play is pure hell, I'm forced to switch stations when they have him barking out Rocket games.