Or could be the fact it's probably a united song as they make most of them up like as follows:
When Johny goes Marching down the wing
O'Shea, O'Shea
When Johny goes Marching down the wing
O'Shea, O'Shea,
When Johnny goes marching down the wing,
The Stretford End will stand and sing,
We all know that Johnny's gunna' score
Even goes in with the title of the song and to be fair this came first!