Don't forget that Kuma actively 'shared' Fumo around as a young thing, and had Sule as primary babysitter... she's a smart chimp, and knows that Sule's line and the males' in particular political status is the key to going far in the troop... she's not dumb!
I'm tipping that at some point we will see Sule as alpha, and maybe even later down the line, young Fumo will assume the role.
T.
I just assumed Sule was the most interested in Fumo, but that makes sense since Sembe wasn't allowed much access in the early years. I saw a video of Sembe getting bitten (playfully) by a young Fumo and being very patient. Kuma was hovering over them like she didn't trust Sembe. I've seen photos of Sembe grooming Fumo in the last few months/year or so.
I think Fumo will be the future alpha male. The adult males are too close in age to Lubutu for them to have the advantage of youth, but especially for Shabani, Chimbuka and Sandali, Lubutu initially had the advantage of age. Sule, and particualy Fumo will be in their prime when the others are heading for their late 20s/30s.
It'll be interesting to see where they go next with introductions, they still have:
Spitter
Koko
Lisa (and Liwali)
Sacha
Shona
Kuma (and Fumo)
Furahi
Shikamoo
Sule
I'm guessing Lisa and Liwali will be introduced next, to ensure Lubutu has support in his alpha role against Shabani and Samaki, and prior to the introduction of Furahi or Shikamoo.
Then Spitter, Sacha, Shikamoo and Sule. If Sacha is to maitain any sort of calm, I'd definately recommend the presence/assurance of her mother and two sons. Shikamoo and Sule would also have the oppotunity to bond with the new females before aggressive/potentially aggressive individuals like Koko/Kuma are added.
Then Kuma, Furahi and Fumo. Furahi I'm guessing will be introduced with Kuma and Fumo to offer additional protection to Fumo, though I doubt he'll need it with Kuma as a mother. I'd actually be more concerned about her being aggressive to the new females.
Then Koko and Shona. By this time, the new females would have had time to form alliances with the males and hopefully not be so vulnerable to attack by Koko. Shona is a low ranking female and unlikely to cause any issues. I'm surprised she wasn't introduced earlier tbh.