Nearly all those stats from the left wing were in the Austrian League, which is MUCH less competitive, you can trust them about as much as you can trust a striker's figures from the Dutch League.
So, personally, i don't think it's that he is much better in that position, just that it was easier to post such stats in a league where there was a wider gulf in class between some of the lesser teams.
The Right wing stats are likely to be the more reliable.
Maybe, trying to break simple stats down can lead to a deluge of context, but even if you consider his right wing stats (which may also be wise because it's where he would be likely to play in our set up) then that's still 17 in 30 for G/A, which over 38 games translates more into between 19/21. Not to be sniffed at when you consider his skillset should release both Phil and Firmino to contribute more numbers, as they will have a pacey player stretching the the gane lengthwise and giving them both more space to play in and a legitimate target for through balls.
The whole thing stinks of sense. Right age, right position, right skillset, for the right for the principles of play, right price (Common', £30m translates into about £17m 5 years ago, it's a good deal in a world where that money might not get you Troy Deeney).
I'm delighted. Klopp has rated him for a long time and watched him develop - if any team in the world is likely to get it right after that, it's Klopp and his team.