Is prohibition affirmed if there is doubt about the number of sucklings or the اصل of breastfeeding, and can breastfeeding be medically proven in this case?

Doubt regarding the origin or number of breastfeedings does not establish prohibition, because "certainty is not removed by doubt," and the default is non-prohibition. The Sharia has indeed prohibited through breastfeeding, and the Prophet, peace and blessings be upon him, said: "What is prohibited by lineage is prohibited by breastfeeding." The wisdom you mentioned might be a reason for prohibition, but it is not necessarily the sole reason. Some jurists have held that prohibition is established even by a single suckle. As for medical analyses, we have no knowledge of them.