No. The D9A/B is an inherent design from Renault Trucks after the latter was taken over by Volvo. It just fits well in the middle of Volvo's engine range and is more suitable to heavier duty work which the D7-series engine will be a bit of a push, whilst the top end D12-series engine is an overkill. That was how the engine got brought in to replace the D7s on much of Volvo's bus range (except the B7RLE).
As GU657 mentioned, the B10T is a tri-axle B10M. Contrary to the myth, the Olympian never had a Volvo product code during it's production life.
