I'm late to all of this, but my impression is he is not too big as someone training the horse or riding it now and then. But, if he were purchasing a horse for himself, I think he would be better matched with a larger horse.
I feel the same way about myself....I might hop on a friend's horse for a ride or two and feel a little big but the horse could carry me fine. But if I were looking for a horse to purchase, I would want a little larger horse because it would be a long-term thing.
Then I keep reading how larger horses don't stay sound as smaller ones, so who knows? But I feel more matched to a horse that is say 15.2, 1200lbs than to a 14.3, 900lb Arab (although I have owned and ridden both). I just feel I look better on the larger horse and not like I'm going to hurt it! But that doesn't mean the Arab isn't just as capable or even more so.
The horse that was probably my best match was only 14.3 but he was a Mustang that looked part draft. He was a 14.3 tank, so height isn't everything either. And then there are some tall, fine boned horses (like some TB's) that even though they are tall, I would feel too heavy for.