The most common two definitions I’ve seen for pansexual/romantic are ‘attraction to all genders’ and ‘attraction regardless of gender’.
The most common two definitions I’ve seen for bisexual/romantic are ‘attraction to two or more genders’ and ‘attraction to more than one gender’.
The most common definition I’ve seen for polysexual/romantic is ‘attraction to multiple genders’.
None of these definitions are transphobic or exorsexist and none of these orientations are inherently transphobic or exorsexist.
Is there overlap between the definitions of them? Yes, there absolutely is overlap between m-spec orientations.
Does that mean that any of them are invalid, pretentious, or unnecessary labels that no one should use? No, people should be free to use whatever labels they damn well please.