Actually this picture has me thinking 7.5 is close. Bones' fingers probably go another half foot past the picture. Bones' arms look more flexed as Gustaf's are more straight down. Even if you give Bones a 2 inch one arm advantage, that times 2 is 4. Then his shoulders are much more broad than Gustaf's. I can easily see the measured difference being pretty close.
Of course. I forgot its from finger tip to finger tip. But only up to the knuckles counts in any significant way.
Having said that, you're exaggerating somewhat. To say Bones fingers go another 6 inches off the bottom of the image is a lot. Even if correct, ITs not like Gus stops there. And, as I said, Gus shoulder is clearly higher then Bones. I'll stick by my guns. I believe Bones arms are each at most one inch longer. Also, to say his shoulders are much more broad? Really? It looks marginal to me. Even to the point where I put the image in photoshop and measured the distance from the middle of the neck to the left shoulder. Bones is no wider then Gus going by the pic. If anything, Gus was a few pixels wider.
Going by the pic, of course. Not saying anything is fact. But going by the pic, Bones is absolutely not much longer then Gus.