I know in the Luangwa of Zambia, old time PHs use the term kakuli for old bull buffalo.
As to the OP’s question… Keep in mind there may be a huge difference between the common trophy standard of the 40” bull and a truly old, heavy bossed buffalo that is broomed, broken or never was 40”. Smooth, soft or hairy bossed bulls that are fast growers on a good diet many times exceed 40” at a relatively young age. They are not considered trophies by most. IMO, except for fringe geographic range areas, most common countries where buffalo are hunted, there is potential for good quality buffalo. The best bull I’ve ever seen live was an old monster with broomed tips in the middle of the BVC in South Central Zimbabwe. The next largest was a mounted specimen taken by a PH in RSA. Tanzania has a reputation for good buffalo but I don’t know there is a real size or trophy difference other than a big price tag for hunting legendary, large tracts of free range attempting to capture the flavor of the golden age of the safari from the past.