Because of the way the stadium planning has developed, it would be a disaster for Cas to merge, if we assume that the merged club would be playing out of Newmarket. To be no longer called Castleford, no longer playing in Castleford, and worse in the stadium earmarked for Wakefield and within the Wakefield boundary, it would be like being the Sheffield end of the Huddersfield merger.
Also, why on earth would Glover want to merge his company with another one? Who would overall control. The asset you would bring to the table, Wheldon Road, would settle debts and add to the team in the short term, but in the long term wouldn't last too long.
If we assume that one of us is going to go, and that Newmarket is going to be built, Glover has got the chance of having complete control of a Super League team playing out of a new stadium, or sharing control of a Super League team playing out of a new stadium. So which is Glover going to go for?
As for club success based on local talent, if Wakey were the only Super League club in the district, then all the young talent would still go through Wakey, and so again why would Glover want to merge? If the stadium holds 12,000, given current crowds, an average of 10,000 is achievable, particularly with the benefits of something new and shiny. So how much extra would a merged team bring? Even if it filled it every week, Glover gets a 20% increase in revenue but only half the return. I just can't see how it would be remotely in Glover's interests to merge.
What it demonstrates is the arrogance of RL people who follow the bigger clubs. When Bradford were in dire straits last year, did anyone suggest a merger with Leeds or Huddersfield to save them? No, they didn't.
One club in the district in Super League would thrive more than the two individual clubs, maybe, but that doesn't mean a merger. And merge and leave Wheldon Road and you're gone for good.
PS: if they do merge, the name would have to do a Wests Tigers. Trinity Tigers might work.