Was Werra's staff original plan with the Palais des Sports-event (the actual Dome de Paris) to plan a fara-fara against JB Mpiana's event at Olympia, but them not being able to rent the hall the same day ? Because Werra's concert at Palais des Sports was on September the 4th and JB Mpiana's event at Olympia Bruno Coquatrix was a week after.
Btw the contract to perform at Palais des Sports came from concert-promoter Dario Kindongo, who contacted him, after that Wemba's staff asked Werra's staff to cancel their event at Olympia which was planned on 10 July 1999. Because Wemba would perform the same day in Brussels at the big Forest National (8.400 seats) to celebrate his 50th birthday and needed the support of the whole community, fearing that he would not sell out the venue like JB Mpiana who performed a month earlier the same day at Zenith de Paris when Werrason performed at Villejuif.