I doubt anybody here is well versed on the namibian boxing scene
. I dont really think you can have a betting edge here unless you have actually seen the other Indongo fights. Plus the KO against the Troyanovsky was not a domination or anything it was just a punch that caught him cold. Really hard to handicap the fight correctly with the info the average non african boxing fan has imo.
With that being said if you put a gun to my head and made me bet I would bet Indongo.
EDIT: The expert move is to search south african boxing forums and see what the posters there think imo