An M11x is a PC gaming laptop. You are comparing Apples and Oranges. As a PC gamer myself, I understand all about heat and over clocking and voltage. And I spurned Apple for years for not letting me tinker with the innards of their computers.
Now I am older and wiser (and lazier) and I just want a laptop that works. The Apple model is completely different. It is not designed for the tinkerer or the over clocker or the person who obsesses over temperatures and SSD performance and things like that. It either works, or it doesn't. There is no over clocking or customizing or tinkering not sanctioned by Apple anyway.
It is entirely possible that an Apple laptop be defective to the point that the processor overheats. I mean, I've seen weirder things happen. But if the systems is operating within the manufacturer's spec, and you are not comfortable with that, returning it is the only viable option. Opening the thing up, putting thermal grease, under clocking, changing voltage (if even possible) is a PC guy's game. And a fun game at that. Apple is just not built for that. Apple is built for the rest of the world who just wants their computers to work. IMHO.