I've fed Strategy to performance horses for years any only changed due to a same quality feed for less money.
I've also used the so called "junior" feeds on all ages of horses.
If you really read the labels, the different mixtures are so close that for the most part they can be interchanged.
If you are currently happy with what you have, don't let someone else opinion change your own.
Only look to a diet change if you are looking to a specific reason for change.