They say to
measure the length from the tip of the longest finger to the ground.
Did they ask for glove size? Tommy Armour measures to the lowest knuckle when middle fingers just touch the fleshy pad under the thumb. Ping has a chart that brackets height between 5''7" and 6'1" That should cover about 85% (my estimation) of the general public! There are other ways than just "dominant" wrist fold to floor (which does not take hand size into consideration) I am not arguing the measurement method! I make my living fitting and building clubs so I won't buy components from any company that offers assembled product to the general public. So this company isn't going to do business with me anyway.
You can't buy a game but you can buy better clubs from me!
Arnie