I thought there shouldn't be any difference if both the shoe and boot are of cordovan leather and on the same Barrie last. I am only worried about the boot being tight compred to the shoe, not the other way around. I can understand if CXL leather boot is slightly snug compared to the cordovan leather shoe on the Barrie last. Unfortunately no one carries boots in the C width. It will have to be MTO for both the cordovan and CXL Barrie last boots.