their difference in size matters. He measured out at 7'0 with no shoes and Davis at almost 6'10. About a 2-3 inch difference. And that's not always important because of things like a long neck.
The big difference is in wingspan and reach. Davis at 9'0 and Gobert at 9'7... That's the big one. Davis is far more athletic so height means little, but reach is big. Reminding him of Davis is reasonable. I don't think he meant a size comparison.