I can agree with that for the most part. I think it's Rubio that has the strategy, long term, of trying to keep Trump from 50% of the delegates, the establishment doesn't like Trump or Cruz. I think it was Lindsey Graham who said if you killed Cruz on the floor of the Senate, be tried in the Senate, nobody would convict you. I'm not sure who the establishment hates more, Trump or Cruz.
http://www.cnn.com/2016/02/26/politics/lindsey-graham-ted-cruz-dinner/
Cruz is hated, Trump isn't trusted. No one knows what Trump is thinking, so the Republicans are scared. Cruz is a sell out who will beholden to a few people, not even the establishment! Rubio is a toddler with big backers. I think each candidate has a positive and negative.
It is generally agreed that Rubio seems the best General Election candidate, though against Clinton or Sanders in a debate he'd be clobbered. Rubio wouldn't push away support for the Republican party, but he'd have a hard time convincing undecideds that he is better than Clinton.
Cruz, no one likes him, not even his dog. But he is a wannabee conservative. That likely means that the Republicans can survive House re-elections and the losses in the Senate aren't too bad and the Democrats end with just a very small majority.
Trump, Clinton won't need to spend much putting together ads. She'll just find the worst half of the stuff Trump has said on video, put it together, and run it. Trump will be trashed in a couple of ways. Firstly, the terribly disparaging things he said about *insert race, people, creed* in general, and then his expected flip flopping, "Mexicans are rapists v. I love Mexicans". His career as a businessman will be exposed. He isn't a building, he is a labeler. He labels his name on things and tries to convince people that that means something. The mystique of his character will tarnish, which could mean his support goes from 45% to 35%, the true believers. This could put the House at risk of turning, a particularly unlikely event that only Trump can make possible. But on the other hand, Trump has pretty much made liars out of everyone when it came to his political demise, so you can't just write him off, because he has managed to do the unthinkable. The High School class clown / bully alpha male is leading the Republican race at this point (I didn't think he'd be in the race by Iowa!).