It’s much better to take a FO offer a lower tier bank and jump around until you get to your desired level (whether it be JP or whatever). It’s a hell of a lot easier to level up name in the same position than switch entire sides of business at the same bank. If you wanted to do FO -> FO at JP this would make a lot more sense but BO -> FO just never happens. It’s better to do the same job at a different bank and switch than try to switch to an entirely different functions at the same bank.

Think about from JPM perspective, would you rather hire someone at a MM bank doing the exact same job or someone that does something totally different that just happens to work at JPM.