Not exaggerating at all. From what I can see the pic stops BEFORE Bones knuckles. Looking at my fairly average hands my middle finger is about 4 inches. Bones is a 6'4 black dude who's brothers play football. His hands are probably huge. Half foot more is actually on the low side in my opinion. Bones probably has was bigger hands than Gustaf.
Ok. But im saying that Bones knuckles are no more then two inches below Gus. And Gus shoulders are at least an inch higher. Assuming the width from shoulder to shoulder is similar, then a 2-3 inch difference is all I can see at most, going by the pic. Not 7+. Even less if we only count up to the knuckles.
Bones always looks massive on fight night because his opponents are considerably smaller. Gus is a beast. Its going to be weird seeing Bones in there with somebody like that.