Gullherme, you’re right —
John Waynes big bay with the blaze, Banner, was a tb. Now, JW was 6’4/ 300 lbs in True Grit> where he’s holding the reins in his teeth) However, it is said, the horse did struggle with his weight on certain stunts. In ElDorado, he was riding a grey roan appy, Zips Cochise…that he hated cause he was too small, (obvious to us if we watch the movie)…but the producer owned the horse and wanted it in the movie. <sigh> poor JW cursed a lot !
I have a fellow coming today to look at a horse> hes 6'4"/250. I honestly doubt even my 16.3 monster boned turf hose with size 2 shoes can hold him. Yes, that mounting *straddle& groan* test is one I use also.
I do notice too, that inexperienced riders have a tendency to want to [U]stand [/U]in the left stirrup, pulling the saddle & back badly, so its not always weight that causes this ... but it is another measure of suitability.
I'm of the camp that big people need big horses and follow the 20% rule --- 1000lb horses max weight 200lbs/ etc. In our hunt club, there was never a man of stature hesitant to ride half-drafts or even full in order to have a full day of hunting! In my younger days, I showed jumpers against a gal who rode a full that flew over fences, challenging me at every turn!
I find drafts(x's) very comfortable -- there's one that ponies at the track, smooth as silk.... and keeps up just fine with the tb's.
I could give, as many of you could, lots of examples and excellent reasons for bigger people to work with these bigger horses.
ps: simbalism: Ive met you …! there isn’t a horse in my barn you cant ride 
