First off. . .Nash is retarded. Most of his opinions, while containing a shred of truth, are usually trolling nonsense. Eddie and Chris really weren't that small, they were just short. . .well, normal height, not short.
When I think of "small" guys, I don't just think of dudes who aren't 6'5" and bigger. Height really isn't that huge of a deal unless you're playing a monster character. And as we all know, there's usually not that many of those floating around at once.
That siad, it does matter (in terms of musclular appearance) because it's a scripted show with power fighting in it. The appearance of being a powerful force is more important than being a good fighrer off camera in a dark alley or something. These guys aren't actually fighting, so what possible MMA or boxing skills they may have don't matter. This is why comparisons to MMA and boxing, where a small guy can win at times, don't matter. It's the perception that matters here. And the common perception is that a dude that looks like Ryback would curb stomp a dude that looks like Punk.
Not to pick on Punk, but just because OP used him as an example, let's compare him to other heroes. Does CM Punk look like any of the following kids' heroes?: Superman, Batman, Incredible Hulk, Thor, any combat-oriented GI Joe, Captain America, Wolverine, Cyclops, NFL players, etc etc etc.
The answer is no. Does John Cena look like them? Yes. He looks more like a hero, therefore, despite being corny, is actually far more believable as a long-term champ. So would Lesnar, or Ryback, or Batista, or The Rock, or whoever.
So size does matter in pro wrestling, because perception is most of the deal. Smaller guys can beat bigger guys in actual fighting irl, but it doesn't happen more often than not. Usually the guy who's noticably stronger kicks his ass.
You guys also need to stop lying about people being "juiced" any time they have more than an average-looking build. Try actually doing work in the gym for once. You can gain very noticable muscle mass easily if you just put in a few hours a week for just half a year.
It's as if you guys think you will look normal even if you hit the weights a lot unless you use roids.
I think you're confusing purely just height for muscle mass and power, which is what the OP is speaking about when he's referring to size. Ryback isn't that tall, yet he's considered "big". It's because of his muscles.
Also, you can't seriously be calling Macho Man and Bruno Sammartino "small". Those guys were swoll as hell.
How are those guys small? Macho Man looks buff as hell, and Sammartino was a huge block.