all partners offer a lesson in practice with them. Your training is your responsibility, and learning to deal with uncomfortable people is part of the lesson. You'll learn no matter who you train with.
All body types, levels of experience conrtibute to your understanding technique. There are different things to understand according to how each execution goes.
Be respectful of your training mates; they are loaning their bodies for you to play with, you can seriously injure and kill someone by mistake; same goes with your own offering. This is a precious thing, not to be blown off by a "yeah but he's smelly" or
"yeah but he's stupid" or any other excuse.