Carragher made a good point on commentary yesterday. He said when Mane first came to Liverpool, he played on the right and was very good. Salah then came and Mane moved to the left. Again, very good. Now, Jota and Diaz have arrived and Mane has moved to the middle. I think you get my point.
He can play anywhere across the front line and be just as effective. Not sure you'd get that from Salah but Salah has Messi moments in him which people remember. As a overall player, in terms of attributes, you'd have to say Mane is more all rounded but Salah, as I said before, has moments in him where you have to just sit back and say "wow".
Both outstanding players and fair to Klopp for getting the best out of them.