I’m with all the others who say “go for it.” I’m talking from personal experience as well. Our family has had a 14.2 Fjord for 12 years. He started out as my kids’ horse. They both, quite successfully, did 4-H, local h/j shows up to 2’9" (he could have gone higher, but DS went off to college), and high school equestrian team with him. My kids are 5’9" and over 6’, both long legged, so you can see, height was no hindrance.
When the kids flew the nest to college and beyond, the Fjord became my dressage pony. I lost my heart horse, a 16.3 OTTB, in January and have now added a second, 14 H, Fjord as a buddy for the first and am having a blast with both of them. I’m 5’9" with plenty of leg and it’s no problem. Our Fjords are sturdy, sensible, and have a great work ethic. The larger ones aren’t all that easy to find. If you like this guy, I doubt you’ll find size an issue. (If you pass on this one PM me with info, I may be interested in him.) Good luck and enjoy. Welcome to the Fjord fan club and keep us posted.