Air freight - Airline name & Flight Schedule, and averaged freight rates

There is one request we constantly get from network countries when we reply with a quote done by the Pricing Manager - the PM does not advise airline name, neither flight schedule...

I understand freight rate is calculated as an average so there won't be an airline to mention. But at the same time these averages can be considerably higher than the best rate available in WebCargo, especially when premium rates are available, bringing the average higher than it should be based on regular rates only...