Time will tell. I think he is a Marmite coach, you will either love him or hate him. That goes for fans and players.
At Saints he had his favourites for certain.
I would not take the word of someone selling a book as gospel either though. Lets face it if you are selling something you need buyers.
At Saints we actually were less successful after he left.
We made many final appearances but wins well they were not so forth coming.
I had no problem with Saints sacking him but they way the board did it was more on a personal than business minded approach. We were top of the league playing great, sweeping all aside, for the board not to hold their powder till the end of the season was devastating. It knocked us right off our stride caused splits in the team, splits in the fans. They could have and should have waited but personal preferance overode sensible planning.
The new guy had to pull the players back into one unit and doing that whilst trying to make it in the playoffs was far too much in the limited time left that season.
From a cas point of view. Milward brought in Scully to Saints, he brought in Lyon, so he can spot talent and despite his attitude to the youth he brought them on too.
Some people like a nice friendly coach to give them a hug, but not all coaches are the same and not all coaches are players pals.
Is he the messiah no.
Is he better than your current coach yes.
AS for him saying Wakey and Cas should merge. Pretty much everyone out side Cas and Wakey tout that old chestnut as some miraclesolution. Lets face it Matterson once he announced he was leaving was suggesting a cut in the league to stop blow out scores like the ones cas suffered against Leeds the week after the CC semi. So Matterson your current coach is not entirely Cas through and through.