I don’t object to rotating the casters. What I’m trying to suggest is not rotating them all at once: staggered shifts lead to greater continuity. A day of cricket (again about 8 hours) will have a team of, say, six guys, each of whom spend an hour in the booth at a time, and one of the two will switch out every half-hour or so. They also try to match all the colour guys with all the PBP guys over the course of the day’s play.
Of course, with commentators drawn from the pool of players that gets tricker, but it was noticable to me that everything had to start over from first gear in each of the rounds of the finals: learning where the various bits of information were, getting their phone out to check standings, not knowing which rules and so on had been explained, and so on. Back to cricket, the other thing this buys you is someone sitting there filling while the other folks in the booth rearrange themselves, rather than getting a minute or two of dead air, and then presumably throwing a nice softball at the guy that just sat down to help him settle in.