Oooh Colbreds, there’s a blast from the past. I’m sure you could of milked pints off the ones we had, if you could of persuaded them to stand up long enough on their terrible feet.The ‘medium’ cup will struggle to fit on a teat that you need to strip out before a decent sized lamb can suck imo.
It is a highly heritable ime, which selection/culling can practically eliminate. Any here with teats like that certainly don’t see a ram again.
On the other hand, my mother always spoke fondly of our Colbred (a Milksheep cross) ewes years ago. You could (needed to!) milk a couple of pints of colostrum off each one and they would still have plenty for their lambs.