This is an excellent topic Teodor!!! and it is indeed perplexing when trying to classify these areas of African edged weapons by using such a broad brush. With my very basic understanding of these weapons, mostly I am familiar with the familiar sabers with open hilt and knob type pommels. I have one (pictured) and I have always regarded it (and the type) as Mandinka, from Mali regions.
Your post piqued my interest to look further into this, and learned a great deal on the terminology here, which I hope I can add properly. I had always thought these sabers (not yet familiar with other variations in form) were termed 'Mandingo' swords. Apparently this term is not correct, and was more aligned with colloquial terms popularized in a book and subsequent film (1975) titled "Mandingo".
While hoping to avoid the unfortunate subject matter, it seems that the distasteful application of this term pertains to West African slavery, while the term in the dictionaries is listed as a people of West Africa in or near upper Niger Valley.
Apparently it is deemed a linguistic classification referring to MALINKA and several other groups, varying in different references.
The point is that properly the term is MANDINKA (also Malinke) and refers to the people inhabiting S. Mali; Gambia, Senegal; and E.Guinea.....who are indeed linguistically linked with the MANDE language.
So it seems that MANDE is a rather safe was to classify the variations of these weapons which are indeed from these regions, and tribal groups of several other Mande speaking nations including Soninke, Susu, Yolunka, and Vai Bissa.
I hope I have described this at least somewhat correctly, and hoped to point out the dilemma in trying to regionally or tribally classifying these weapons, which clearly seem to have certain unique character while having overall similarities.
One of the most daunting factors would be the inherent movements of tribal peoples as well as the complex trade networks through these regions. I was under the impression that the Mandinka were in control of the trade routes in and around Mali. I see now that that would be an entirely ineffective rule of thumb, but the point is that the diffusion of the basic character of the weapon forms and elements would have easily been carried widely.
One of the most notable features of the Mandinka saber that always intrigued me was the FLARED SCABBARD TIP, very much like those on Sudanese kaskara. I always wondered why this feature became situated on these sabers of the Mandinka, but were inherent to the Sudan, exclusively as far as I could find.
I think you are right Teodor, we can do better in classification, but probably more by qualifying the general classification used, and adding qualifiers or sub-classification terms or notes, such as possible other tribal features.
For example, dagger of Mande form with character associated with Gambia or a certain tribal group.
As I was once reminded by a well known author on ethnographic arms, "weapons have no geographic boundaries". This is true, however, there is substance to the propensity of a type in a certain context, and that is where the classification likelihood is centered.
As always, wanted to keep it brief
Best regards
Jim