None of that proves that such an alliance did exist. If anything, it shows that Ron Paul was perhaps friendlier to Romney than the others. Fair enough.
Romney, like most Republicans, at least knows libertarian rhetoric. Santorum openly disdained and tried to crush the Ron Paul movement. If Ron Paul "Teamed up with Romney" solely by going after Santorum, that made sense anyways. And Newt Gingrich wanted to build a freaking moon base
I don't claim to support everything Ron Paul does, he is still a human being after all, but I don't see how he "Sold out" to Romney here at all. He didn't even endorse him. Honestly, I believe Ron would have campaigned for Gary Johnson were it not for his son. Rand Paul is actually a politician, and Ron didn't want to screw his son over. Who would?