I have a coming two year old that is just on groundwork, and will be worked light caveletti at liberty when he turns 2, then broke to ride when he is coming 3. Im going to do a dressage base on him until he is 4.5, then start him on his jump training (small, mind you- just teeny crossrails after cavelleti.)
I dont know if this is correct, seeing as I usually am doing barrel horses, but we shall see how he turns out!!!!
Just make sure he is sturdy enough to handle his workload.