I think the Saturday 2:00 pm slot is like the minor leagues for Robin. They scout talent (new or old) and If Crummey or any other host (including Frosty, Lisa Ann Walker or even Conway) lights up the board and the ratings books, then she will move him or her to whatever major league slot.
At the end of the day, Robin is a shrewd businesswoman. If any hosts garners spectacular ratings or a potential for this, Bill Carroll or Tim Conway Jr are vulnerable no matter what type of "decent" ratings they may be attracting and what type of contract they have. I doubt they have contracts guaranteeing they remain in their time slots.
Both guys are the fluff boys at KFI and fill in for anyone or work any holiday management wants them to work on. Neither are in the league of Handel, J&K or Rush.