My airplane is based at TBPB, off all the light airplanes here mine alone is based on the north ramp with the Airbusses, Boeings, and to be fair the private jets, some ATR's ans a few Twotters, I even have my regular gate (6R) right next to the tower, so used to lots of planes of all sizes looking to park up.
All the airplanes with fare paying passengers get a marshaller, having been given the gate number the airliner is asked to "report the marshaller in sight", once the report is made the final instruction is to "follow the marshaller's instructions" so fsiling to do so would likely get someone in trouble - but I agree the if the marshaller's instructions were going to result in a collision then PIC gets to stop, but not to then doing something further.
As to my airplane, I dont get a marshaller, just get told "taxi to 6R at pilot's discretion"
Overall I think that "I was following the marshaller's directions" may tend to mitigate but would n8t be the basis of a defence.
An interesting question.