If you have never owned a heavy horse before, please don't get a yearling. You would be much better off getting yourself a 3yr old Clydesdale who is ready for backing or a slightly older one already backed. I got my first Clydesdale when he was a backed 4 year old and I was 49. He was an absolute dream horse and I learned so much from him about the proper care of my own heavy horse (even though I have been around heavies all my life). Owning your own is very different. I learned about feeding, foot care, riding style and how it feels with a heavy. Totally different from riding a pony, TB, cob, hunter or sports horse. I waited another 18months before I bought myself a 'baby' Clydesdale. He is a yearling and very, very different to my now 5year old. His nutritional requirements are different, he is not at all sure footed (think Bambi on ice) and is growing at a rapid rate and his body shape changes by the week. He has benefitted from having 'horse' buddies who are teaching him how to behave like a horse and me, teaching him manners around humans. Both my Clydesdales have the most wonderful temperaments but if you want good advice, unless you know exactly what you are doing with Clydesdales, don't buy a baby/yearling for your first venture. Go for a more mature horse, they don't stop growing until they are 7 anyway. You are right that they can't be backed for riding until they are 3 year olds and in the UK, they will not be considered for pulling work, cart work until they are a minimum of 6 years old. They take a long, long time to mature but I can tell you, they are worth the wait. Good luck and there is no such thing as a 'bad 'un' in Clydesdales.