Where's your argument for his type then?
If you know MBTI, Tony's work speaks for itself. A bit of an asinine answer, perhaps, but it's simply true. You're dealing with one of the most sensitive, nuanced, subtle, versatile and powerful character actors who ever lived. That is what a dominant Fi with Ne aux looks like. ISTJs who go into acting--and some do--are...Well, to avoid bashing them, Jack Webb was indeed an ISTJ.
Jack:
YouTube - Dragnet Jack Webb "What Do They Pay You?"
Tony:
YouTube - Magic-1 Caught in the Act
YouTube - Shadowlands 2
YouTube - Nixon (Anthony Hopkins)- California Governor Race 1962
YouTube - Othello (Anthony Hopkins): Iago tells of a handkerchief
YouTube - The Elephant Man Part 5
Etc.
But to spell it out more clearly, it might be useful to read bios of Tony, interviews, etc.--and certainly to read what others who know him have said about him. ENTP friend and colleague James Woods, for example, is one of many who have commented on his introversion. Richard Attenborough and others have remarked on his extraordinary sensitivity...And certainly, there is no question that his iNtuition is extroverted--here's but one example:
YouTube - The Ed Bernstein Show - Interview with Anthony Hopkins
FWIW, a good online bio:
Anthony Hopkins - Biography
Quotes about Anthony Hopkins
"Out of all the great actors, he has a strong element of doubt in his make-up, and that doubt is what gives him some of his margin of greatness." - Oliver Stone
"Tony is so relaxed and casual, that's the great thing about him, what you see is what you get, and what you get is great." - Julianne Moore
"Tony is so powerful in his understating: his muted colours are better than everybody's primary colours. For me, he is the Beethoven of acting - profoundly creative and brilliantly orchestrated." - Mel Brooks
"He is one of those actors - and they are rare - who can convincingly portray a man of genius." - James Ivory
"Tony has this extraordinary ability to make you believe when you hear him that it is the very first time he has ever said that line. It's an incredible gift." - Sir Richard Attenborough
"He forgets how good he is." - Ridley Scott
"Who needs special effects when you have Anthony Hopkins?" - Scott Hicks
"Anthony Hopkins is sooo........I'd just give it right up!! It wasn't until I met him that I was utterly sold. This huge energy just pours off him - it was like he lassoed me, reeled me in." - Julia Roberts
"It was so gross! It made me gag, but then I realised, that's Anthony Hopkins eating me - that is so f***ing cool!" - Ray Liotta
"Nobody delivers a line better than Tony." - Alec Baldwin
"I would pay to work with Tony, he is the ultimate package. And forget the voice, the eyes." - Julia Roberts
"I have huge respect for Tony, truly one of our greatest Actors. He's a heavyweight, he's Holyfield, I have years before I understand where this man is coming from." - Brad Pitt
"A seething mass of contradictions, almost impossible to understand, very easy to love." - Jenni Hopkins (ex-wife)
"Working with Tony was a great experience, it's like having magic in your hands." - Oliver Stone
"The fact that Tony hasn't got an ego is the sexiest thing in the world." - Catherine Zeta-Jones
"Tony just completely fills a mansion, he really does! I've never seen energy like it - he's so dynamic. He's honestly the rawest talent that I've ever been around, even when he thinks he is screwing up you just wish you had that as your scene. He's an incredible presence and he works really hard." - Claire Forlani
"Tony was, and is, a wonderful man who lives everyday with the burden of genius." - Dame Judi Dench
"What I worry about is, are they fun to work with, are they nice, are they funny, are they easy to get along with. Tony was all of the above. This was the only time that I've ever been on a film where I've stepped outside myself and been aware that I'm actually directing someone of that calibre." - Jon Turteltaub
"Underneath that icy blue gaze - you can see the flames." - Emma Thompson
"For Tony, it's either black or white, up or down, all or nothing." - Jenni Hopkins (ex-wife)
"Anthony's voice, the way he says any line of dialogue from Hannibal Lecter, it sends chills to everyone." - Martha de Laurentiis