Yeah I know what you mean -A-. I have been down that road a few times. You have 2 SO beans that are fantastic on their own, but when blended you cant get the extraction or the flavors that you are after.
As it turned out, the thing that was letting the "blend" down was not being able to achieve a great extraction due to the grind coarsness required. 1 bean needed a very fine grind on the mazzer while the other was on the coarse side. How would one get around this?