Well Yorke and Coveny are the same age anyway, so there's no problem there. While I'm all for youngsters playing, last season showed that at this level of football (where the standard's good, but not world-class) experience is useful. Everyone knows that the Knights need New Zealanders to be a significant part of the roster to get the crowds interested, to build up a stronger team spirit and through that the club can develop and the team can start playing better - otherwise there won't be a club there in a couple of years time.
As for a marquee player, it would be a boost for them but I don't think they could attract (or afford) someone of Yorke's calibre. There's no way Aloisi or Cahill would go there. Cahill's not coming back yet - his career is on the up. If Aloisi were to come back now it would only be to Adelaide to play with his bro and to be closer to his family. But even that's unlikely, he's still got a couple years at the top level in him.
It's good to see them looking at local Kiwi talent as that will benefit the club long-term if some of those players can cut it. I'd like to see them scouting abroad also. Buari seems a good signing, but I hope they don't remain too anglo-centric as they can get better value for money looking outside Europe: Central and South America, Asia, Africa and inject something different into their club and the league as a whole.
Anyway, it's a shame they couldn't get Coveny.