Across one motherboard, most of the time. For simplicity in assembly, most of the FETs (except where difference is needed or to save money) will be the same size part - Physical size, rating and type.

Across different models and brands, it can be all over the place - Different sizes, amp / voltage ratings, heat dissipation, and junction type.

Many manufacturers will offer parts of similar spec, generally if one finds one of the same size / rating / junction, it'll drop in and function normally.