In my years of playing in the 19 twinking community, I have always felt that NA failed to back up the majority of what they say.
In terms of those who speak the most, do the least such as Voc. However on EU, the people who used to talk the most such as Vianco etc were always able to back it up.
When "Clash of the Titans" happened in MoP because of Raw Talent dodging Tough Love ( I.E the best NA guild apparently vs the best EU guild ) clash of the titans was basically the best of NA vs the best of EU +1-2 people.
Of course the EU side one most of the games.
From what we see in the last twink cup, regardless of whatever reasoning. EU stomped on NA ( GSC justice was 7/10 EU I think and SR was all NA/Oceanic ) in mid and also objectively.
Any class you really compare EU is better than NA.
However NA does have very good leader which I feel are equal to EU. Such as Fearthebuns, Saxxon and of course Pizza.
But EU as I said equally has good ones such as Rasmus ( Who I think shot called in the last twink cup ), Daniel Liberal Blue ( Who is a better shot caller than priest imo ) and various other ones from over the years such as Nicozy etc.
EU>NA is every aspect of the game I personally think.
The only thing NA would be equal to with EU is comparing FCs and Shotcallers.
EU Mid would 100% stomp NA mid.
EU objectives would be cleaner than NA objectives in terms of hunters, if you are to compare such as Stabilt to Agntgrizzle ( Who are both great players ).
So with this in mind I would say EU>NA easily. If there was a best of EU vs NA game. Out of 3 games I would expect either 3-0 wipe or 2-1 to EU. With the only reason being a dumb call by an EU FC, not to name names.
Also the average EU casual player vs average NA casual player isn't even up for discussion really, the average NA player such as Voc to compare to someone that just joined the 19 bracket on EU wouldn't even be a close call choosing the EU player.