I messaged my Dutch friend, who is a massive Feyenoord fan, for his thoughts about Arne ... and to apologise for stealing his manager. This was his reply ...
"I don't blame you for stealing our top coach, like you did before with Dirk Kuijt. We're happy that he's leaving for a proper team. Last year he almost left for Tottenham. We'll sure miss him, but it was inevitable. He's really good, could become as good as Jurgen Klopp. He made Feyenoord from average to a top team. This year we were really good in Champions League, playing better than Atletico Madrid. But unfortunately, we need to learn to be smarter and cleverer.
He's a brilliant tactician, always remains calm, gives very nice and friendly interviews, replies to critical questions with humour and never gets angry. You don't see that a lot. And, most important, he's capable to get every player to perform better than before. For example, Kokcu, was an average player, and a difficult person with problems in his family. He gave him attention and trust, and within half a year he became captain and the best player on the pitch. After his transfer to Portugal, he never reached that level again. And there a more examples like that.
I hope that this convinced you. Give the man some time, and he'll probably become one of the best coaches you ever had."
High praise. I was on board anyway. I thought his leaving videos at Feyenoord showed Klopp-like characteristics. But I'm further reassured by my friends comments. He was spot on about Dirk Kuyt at the time ... he said then that Kuyt would never be the best player in the world, but we would love him because he always worked 100% for the good of the team.