High Drain Current MOSFET vs Low Drain Current MOSFET for Synchronous Buck Converter
Absolutely no problem at all. The high current FET does not know to behave any differently just because you are running less current through it. Provided that you have correctly calculated Rds(on) at the correct gate voltage, it is up to you to decide what to use.

Generally speaking, higher performance (lower Rds(on)) devices are more expensive, and higher current devices are both more expensive and physically larger. If neither of those applies or bothers you, crack on.