Colibrì, the power required to drive the two pumps is minimal, respect to, say, MCP,( less than 10 HP, I imagine), their contribution to the Bearings reaction is truly minor, the side force of the two spur gears being very small, respect to the balance of the bevel gear. The bottom roller bearing is there to support the Shaft, its main loading IS due to the bevel gear mesh, and the bearing is smaller than the top roller one because (like in a lever...) its load is inferior since its distance from the gear mesh is bigger.