A lot of people don't and I love that sometimes. I think it works better here than in some other cases because David doesn't have a lot of canon baggage with Clint, but rather knows his protege well, and other teammates of his, so he doesn't come in with as much 'wow I'm comparing you to this other version I know' than a lot of other MCU characters. Means he can more easily see and respect Clint for who he is as MCU clint, and then maybe share stories on the side if Clint is curious, and only then.