From beginning to end, Joe Ga never took the so-called 'God's Armament' seriously, he wasn't even very motivated to eliminate them.
Because he was a contractor, not a philanthropist, Congo had already shown enough sincerity, and if Uganda didn't make a move, then the deal couldn't happen.
Now with Aaron's support from behind, Joe Ga had all the time in the world, he could even tailor the timing for them.
Staging a military coup would take a long time, and Joe Ga needed this 'coup' to follow the path he had envisioned, otherwise, what was he aiming for?
At this point, to inquire about the people behind Aaron, and how they orchestrated the attack on the French, would seem a bit impolite.
Since the French themselves chose to trust Aaron, it was only right for Joe Ga to pretend he knew nothing and earnestly earn his money, which was the most appropriate course of action.