Sychronous generator vs dc generator
Presuming that both devices had their excitation set to allow them to deliver rated power at rated voltage, a synchronous generator with separately excited field winding and a DC generator with separately excited field winding will both suffer from thermal overload of the armature winding in a sustained fault if the excitation is held constant.  The thermal overload may permanently damage the winding depending on the duration of the overload.  The DC generator may also suffer damage to the commutator and brushes from the elevated armature current.