On top of that, Russia probably is concerned that they have few global strategic partners and is on the hunt for allies wherever they can find them. Although Rwanda probably can't help out in too many places (eg. additional ports in Africa like the Chinese and other are trying to secure in places like Djibouti) it is still part of the UN and could help project power in the region & serve as an example of the kind of support Russia can give to Africa. I think in S. Africa they're trying to engage in military partnerships and recently sent a few bombers down.

https://www.military.com/daily-news/2019/10/21/russian-bombe...