Not saying you are wrong...just British :). There are two ways of doing it...The Brit way and the other way. The Brit way is based on the fact that the original numbers went like this...
11 10 9 8 7
6 5 4
3 2
1
As things shifted the numbers stayed the same as they moved to their new location on the field. Thus you have what you posted. Most of the rest of the world use the numbers I posted.
Obviously your way is more traditional, and the one you quoted is bastardised. However full backs, centre halfs, inside forwards etc have been used out of context ever since the 2 35 went to 3 2 2 3, and the number in the continental game are more the 4 1 1 wide 2 1 1- with the last 6 being 6 8 7/11 10 9.