I never use frequency of a haplogroup as the sole measure for my views on the origin of a haplogroup, I use other archaeogenetic markers including craniometrics, archaeology and linguistics.
The presence of a paragroup is not always the top mean to determine a haplogroup's origin , unless it benefits Europeans. A good example was R1-M173, the pristine form is found in Africa, but Europeans claim R1 originated in Eurasia, when V88 is the oldest R1 clade and R-M269 exist throughout Africa across African linguistic and ethnic groups.
Greatest diversity is not always a good measure of origin because the location of a particular ethnic group may not be representative of the history of that group for example, researchers have situated the original homeland of the Bantu in West Africa, due to the variety of Bantu languages in the area when in reality the Bantu expanded from the Nile Valley into West and Southern Africa. Moreover, the greatest diversity of genomes is in Cameroon but it is never recognized as an origin area for any haplogroup.
Other researchers claim the M haplogroup originated in India because, of the variety of M haplogroups in South Asia. But the Dravidian speakers who demonstrate this variety belonged to the C-Group in Africa and only entered India 4.5kya. This along with M1 spread throughout Africa, supports an African origin for hg M.
Haplogroup N, according to ancient mtDNA (amtDNA) was first found in Eurasia among Aurignacian people. The Aurignacians were Khoisan who crossed the Straits of Morocco to enter Western Europe. Since they took N into Iberia this haplogroup had to have originated in Africa.
We can believe that haplogroup R probably originated in Africa because V88 is older than R-M269. In addition, R-M269 is spread throughout Africa and carried among many Africans that could not have admixed with "Europeans", including Khoisan.In addition, whereas there is no history of an Eurasian invasion of Africa, we do know that the Kushites who spoke Niger-Congo languages and carried haplogroup R did invade Eurasia.
In summary greatest diversity and paragroup means are not a good indicator for a haplogroup's origin. There is also great diversity of hg M in Africa.