Of course drafts can gallop - how do you think all those knights of old dodged the arrows.
But before you try galloping your heavy horse of whatever breed, read up on Newton's Theory of Motion: -
"The heavier the weight, the faster the speed, the greater the force".
So the problem only starts when you think you ought to be stopping
and going round blind corners is definitely a bit risky.
As long as you pick a nice long, flat, hard, sandy beech at least a mile and a half long, wth no rocks, no children, no dogs on leads, no balloons