No justification for that whatsoever, Arteta can’t be said to be better than Ten Hag because all his time at Arsenal hasn’t won him any trophy. Ten Hag has spent two seasons and have won two trophies already, in every season he won at least two trophies. Mikel Arteta may have shown great performance with Arsenal and has improved them in all sides and made them more competitive and successful than before but without a trophy to show for it, it’s meaningless. That is why they need to do better in the next season, they need to fight to the end and now allow another team to take over from them as they do in previous seasons. A coach success is only calculated by the number of trophies and not the number he finishes the league with every season.
That's it. The point is to compare the trophies won by Ten Hag and Arteta. Most of us use trophies to judge a coach's success. I found something interesting.
I can't really say that if Arteta is much better than Ten Hag in term of achievements. To be fair, Arsenal plays better than United in term of gameplay. That's a fact. But, Ten Hag has won more trophies than Arteta. This is also the fact.