those measurements are taken from fingertip to fingertip and measure the wingspan. usually a person's reach/wingspan should equal his height. mosley seems to have a wider body which might be part of the reason his 'reach' is more than cotto's. if mosley was the type of fighter that fought tall and used his reach...that measurement might be significant...but it's not because he likes to fight on the inside. it gives him no significant advantage. that 7 inch advantage is split which really equals 3.5 inch advantage.
For the record, I'm 5'9.5" with a ~72" reach (fingertip to fingertip span), I have long arms and about average shoulder width (no gorilla here ) So Mosley having a 74" reach isn't too shocking, considering he IS rather lanky for his height/weight.
Mosley lost to technically sound fighters. vernon forrest and Winky Wright are bad-ass technicians and have incredible jabs. Both are MUCH bigger than Mosley. Cotto has a weak chin, doesn't have a jab near winky's or vernons and isn't nearly as technically sound. Mosley is the bigger man too. People forget about Mosley's KO percentage and he's a devastating body puncher too.
Yeah, Mosley lost to Forrest and Wright who are both listed to have the lesser reach. So this wasn't much of a factor. Shane has style not based on reach advantage.