First of all, I've never heard Armin mix 32 tracks in 5 minutes. He had around 80 in his 2 hour yearmixes, which doesn't even come close.
Secondly, I don't see why mixing/mashing tracks up in rapid succession would be the copying of someone's mixing style. It's basically what megamixes are all about. It's not a style specific to one person, especially not Armin who made only 3 megamixes. And if you really have to call it copying then it would be copying the person who did it first, which certainly isn't Armin either. Ben Liebrand perhaps?
But really I don't get why this thought pops up in your mind at all. This is the first time I heard a mix like this, and even if I had heard more I wouldn't think of it as copying.
I don't think armin invented key-matching in mixing. I personally love Shane54's mixing style and a lot of his mash-ups are really good actually. I don't think he should be judged as unproffessional because he made one bad mashup? I mean Armin isn't the greatest every single week on ASOT, he has his bad weeks.