> A chimeric human possessing the capability to produce neither gamete and possesing neither testes nor overies pokes apart that argument

You seem focused on actual when it should be potential. That individual, if one were to exist, would not be able to produce both if their disorder could be fixed. There have been no such individuals recorded so the scientific community waits with baited breath.

> In addition, as noted elsewhere in the thread, sexual dimorphism is typically used to discuss more than just gametes in study of other species, so why not ourselves?

As pointed out in the quote written by the zoology professors, anisogamety is determined thus. Whether other aspects of biology can be determined or inferred from sexual dimorphism is irrelevant to anisogamety. I know you want to make the “we are more than our genitals” argument but it’s just not relevant.