UMOP and USLM are what they are. Both can produce the same results, but they don’t have the same effects. Both, for instance, can produce motivation and get you to overcome procrastination, but one does it as a primary focus (UMOP) and one does it as a side effect (USLM). Likewise, both can make you successful, but again, one does it as a primary focus (USLM) and one does it as a side effect (UMOP).
USLM includes the luck maximizer; UMOP has no such thing. UMOP specifically targets procrastination; USLM does not.
UMOP is generally going to be a more narrow focus – motivation. USLM is going to be a broader focus – success and “luck” with whatever you’re trying to do. If you want the more narrow focus, use UMOP. If you want the broader focus, use USLM.