Ok then show me the polls where Trump wins head-to-head over Cruz.
And apply your same rules to those polls.
This poll was taken Feb 22nd to 28th with 4,200 registered Republicans, MOE of 1 percent. CNN has their own bullshit poll saying the opposite, but with much smaller sample.
"Our results suggest that unless something changes, Trump would emerge victorious in a head-to-head match-up with either Cruz or Rubio. When given only two candidates to choose between, Republicans preferred Trump over Rubio by an 8 percent margin, and they preferred Trump over Cruz by an even larger 13 percent margin. These results suggest that, at present, Trump's standing would not be diminished even if the race were reduced to a two-person contest."
http://www.nbcnews.com/politics/2016-election/going-head-head-trump-can-rubio-or-cruz-win-n528536
In this PPP poll released 6 days ago, Trump beats both Cruz and Rubio one on one by huge margins in the state of Florida:
http://www.publicpolicypolling.com/main/2016/02/trump-leads-rubio-even-head-to-head-in-florida.html