In the same way that you would probably not complain if someone said Floyd Mayweather is the best boxer ever, without qualifying that you know he'd be beaten to a pulp by every heavyweight on earth.
In the fight game, they use the term "pound for pound" to qualify any subjective judgements and address issues regarding weight divisions and so on.
"Plenty of strikers can score goals," he said, gesturing to the famous old stands casting shadows around us.
"But a lot have found it difficult wearing the number 9 shirt for The Arsenal."