You train horses to see if they are strong or weak in stats. You use that to match them to horses that would benafit those stats in the foal. A horse could show 50 times in a month but it would not increase the stats of the horse.
I enter foals from birth as shows contribute to training. Also they are competing against others that are the same. Before you criticise, it works for me
Sandy if you're premium you can use the barn manager, but I enter at week 4/5 and then the same after they level. I use the barn manager and I also try to hand enter when I can before she does lol
sandy the easiest way to tell is if the horse has 2 bars per level in any discipline, if they don't they're not ready, if they have more than that(like the horse you mentioned) they're going to level up soon, so they'll do better in shows until they do level up :)