Rockhold is technically solid when it comes to his stand-up but it isn't something that comes natural to him.
I have no doubt he can hold his own with most strikers but he gives away a few obvious tells when an opponent tests him.
Vitor gauged his movements by the mid point of the first round. Sure he was on TRT, but the reason the head kick landed was due to the fact that Rockhold would tense up every time Belfort did a feint.
The Dollaway fight highlighted just how effective Machida can be at setting traps. He gauges the movement and responses and picks his moment. Im not sure Rockhold can last 5 round without slipping up.
That being said I wouldn't touch this fight. It's a very risky bet.
Saying that it doesn't come naturally to him is completely subjective.
He has finished and hurt high level opponents with all kinds techniques, including head kicks and body kicks which you rarely see utilized effectively in MMA except by the best of strikers; so calling him stiff is just wrong in my opinion.
And the way you judged his striking based on the Vitor headkick is really a stretch.
You could also judge Vitor's striking based on the Anderson fight, and then judge Anderson's striking based on the first Weidman fight - both fighters looked really "bad" in those fights, yet I'm sure you wouldn't call them stiff or say that striking doesn't come naturally to them.
You really can't pick one or two fights and judge the fighter's whole career and technique based on that. You bring up the CB fight for Machida, but what about 4 decisions in his 5 fights before that? And what about Rockhold coming off consecutive finishes on Bisping, Boestch, and Philippou?
I cannot disagree more with your implication that Machida is some sort of crazy finisher, and that Rockhold's only chance of winning is via decision.
Personally, I see that as upside-down thinking.
I totally agree however that it's an extremely hard fight to predict. Wouldn't surprise me if either fighter wins in any manner, though Machida by submission and Rockhold by decision have to be the least likely possibilities.