Just because you get an LCA as a Capt doesn't mean you're not flying the rotation. It's not as guaranteed as you think. I'm around 30% and don't get many LCA trips. Also, the LCA can swap off the trip until OE is assigned to it, so you might not end up with the LCA as the PBS results showed.

Two examples, 4 day trip this summer with an LCA - the LCA did a quick requal on the first day, I stayed home for the first 2 of 3 legs (out and back) then I flew the third leg to the overnight and the other three days of the rotation.

Second trip, last month, LCA did a 6 month check for an FO in the middle of the rotation. I flew the first two legs, deadheaded on the third leg (of day 1), deadheaded 1st leg of day two then did the rest of the trip.