I don't think the mix is bad at all--I wouldnt feed him pure alfalfa tough.
Depends on what cutting the round bail is really.. what kind of hay is it?
In the second picture he still looks nice. Im thinkin he's going to be tall and lankey when he grows up, lol.
I know it can cause problems in combination with large amounts of feed.. Its most likely coastal.. We're expecting him to reach somewhere between 16hh-17hh!