Ref trans-Sahelian stylistic transmission generally, the Pitt Rivers is reassuringly vague:
"The flaring leaf-shaped lower portion of the scabbard is said to represent the head of a crocodile and can also seen on the scabbard of the straight kaskara sword of the Eastern Sudan, on the opposite side of the continent’s Sudanic belt. Some scholars think the most plausible explanation for the unusual scabbard form appearing in two places over 3000 miles apart is that it was carried westward across the Sudan by successive waves of Islamic warriors over the last one thousand years."
So, like, yeah. OK.
http://webprojects.prm.ox.ac.uk/arms...ica/1929.12.3/
I guess the same may or may not go for other stylistic aspects. Perhaps.