personally I like a bit of inconsistency. Though there is a point where it is no longer the blend of theseus no matter what the tin says.In days of yore, when blenders had reliable contracts with particular growers, crops from several years would be blended to reduce the year by year variation. Think of it as homogenization. Then, adjustments would be made to the flavorings to further enhance the stability of a blend. I think that the end of subsidies to tobacco farmers really set off the changes we're seen over the last 8 or so years.
I think the most obvious solution is to start pricing pipe tobacco the same way cigars are priced. You want that leaf even as a condiment? Well it will cost you the price of giving the farmer a reason to farm it.