but there is always the chance that there could be foaling problems
this seems logical, but I haven't found any statistics to support it. I've even seen a 14hh arab bred by an 18hh percheron and foal with no problems. The one I saw have major issues with a too large foal was a large mare bred to a narrower stud of the same height.
I think foals in general stick to the mares height more than the stallions, and I've heard that said by many an old horseman, so their must be some truth to it. That said, the percheron/arab foal mentioned above matured to 17hh, my foal this year, out of my barely 15hh arab, is over 12hh at 3 months, nearly the same size as his 4 month old half sister out of a 16hh mare. I knew one mare that consistently threw taller, wider offspring, regardless of the stud she was bred to.