Biman have currently 5 wide body aircraft. Recently a Boeing 787 dreamliner joined the fleet.
Three more purchased dreamliner will join the fleet within 1 year. Another 2 wide body will join by lease. So Biman will have 10 wide body aircraft within the next one year. For a poor country like Bangladesh where long distance air travel is still very low per capita wise, 10 wide body aircraft is satisfactory. Even Turkish airlines, one of the biggest airlines in the world has just 92 wide body aircraft out of 300 passenger aircraft. This is the case with almost everywhere. More narrow body aircraft than wide body. Notable exception being Emirates.