That's quite bad reasoning. Firstly using an Alakazam to catch an untrained wild Mewtwo is a very bad comparison. Other than Magic Guard, Mewtwo has an absolute advantage over Alakazam in every possible aspect.
Secondly Zoroak is slower than Mewtwo even though it's a glass canon so Mewtwo would just flatten it before it got to act. Even if Zoroak used Sucker Punch there's no guarantee that Mewtwo will be attacking that turn since it has such a wide move pool.
Thirdly, I'm assuming "normal gameplay" refers to playing the story of the game where Mewtwo isn't available in the most games and is only available at the end of the post game in the ones he's in so there isn't any opportunity to use him. Then you also a multitude of players who flat out refuse to use any legendary Pokemon.
So you think it's simple to just catch a level 70 wild mewtwo with a level 44 alakazam?
And as for zoroark, if you EV train it for speed [which I tend to do with all my pokemon for at least 20 levels, speed is important in all battles], or with the right nature, it could easily out-speed a mewtwo. Focus sash, or razor claw, + night slash, either a one-hit crit K.O. two-turn domination.
Any legendary can be dominated with the right pokemon and the right trainer. And Post-game counts as normal gameplay. The other areas that unlock, and the places that don't have the built-in bans, like Black Tower and Whitetree Hollw.
Another good example, whether you see it as a bad example or not. My prime, Lucario, with Shadow Claw, can easily dominate Mewtwo as well, mewtwo's wide movepool, can't really help it with Lucario's resistances, and Mewtwo's commonly low defense [due to people generally training Sp stats] leaves it open to physical attacks.
P.S. this isnt the thread for discussing this :P
