Ryanair will make any effort they can to put you in the base you request, however sometimes that base is sometimes full. It might be the day of the week what bases are available due to movement within bases, upgrades, cadet training, pilots leaving or just plain requirement, but they will try their best.
Looks like the brainwashing hasn't worn off yet.......
Put this into perspective. 2 FO's on identical roster patterns are looking to swap bases, the swap would mean that both live near where they're from. Swap denied.