Ditto what someone else said - these smaller stallions all have height in their pedigree, and many will throw taller than their own height.
I learned the hard way to buy my short WBs from breeders. Anything under 16 hands is outside the bell curve for WB breeds. You just can't breed for it unless you're infusing pony blood (which isn't my thing) - so you've got to look for those happy accidents.
And no, short horses of quality are not cheaper, sorry to say!
"You become responsible, forever, for what you have tamed." - The Little Prince
The only Goodtimes offspring I ever saw was nearing 17hh and as long as a bus, so I am always shocked when I see him referred to as smaller and throwing smaller. But of course that was only one horse.
Have had two Goodtimes mares one just below 16hhs and one just above. His dam was small, if you want height with Goodtimes it's best to breed to taller mares. In this case it would be a good choice and his frozen semen is excellent.