As a Warrington fan, I think this is an excellent signing.
Mathers is below the echelon of 'top' players for me in terms of ability. However, in terms of what he brings to a club in terms of his attitude, application and work ethic he is absolutely first class. One of my favourite Warrington players and a fantastic antidote to the culture that appeared to plague Warrington before Tony Smith arrived. He played a massive part in our Challenge Cup win last season and similarly again this as we currently look on course for our best league season finish since adam was a lad.
He occasionally makes mistakes. Such is life. The only thing odd about that is that he seems to reserve his for times when he is under little or no pressure. He does the hard stuff better. He is an excellent organiser of a defensive line and I would expect improvements in that area (particulary over McGoldrick). His kick returns have improved over the last 12 months and we occasionally use him as an extra pivot coming out wide. His passing when doing so is a little shaky, hence, I assume, the Hodgson signing.
All in all, you've signed a really good player who will have an impact at your club on and off the field. He deserves to suceed and I sincerely hope he does so at Cas.