I think it comes down to the equipment and what the equipment would 'allow for.' You can swing well out to the right with today's modern equipment. Yes, not exactly advisable...but one can do it and play very good golf these days.
Old persimmon woods and tiny blade irons heads? Fuhgetaboutit.
What sticks out to me about Hogan is that according to his clubmaker, Gene Sheets, Hogan had X-Stiff shafts tipped 2 inches in his clubs BEFORE he discovered 'the secret.' That tells me that Hogan was trying to make his equipment so stiff and flat to essentially 'de-hook' the clubs.
Personally, I think Hogan generated a TON of clubhead speed for that equipment. It's just a visual observation...but I think he probably could swing those clubs faster than all of a handful of modern players could swing that equipment. Generating that much clubhead speed and not being able to generate a post impact pivot, to me, spells a recipe for a big path out to the right. You can't get away with that with persimmon and forged blades.
I think over time the super stiff equipment helped strengthen his pivot a little. But I think he just got to the point where he probably thought of something simple like 'let's try and slice the ball' and started rifling straight shot after straight shot. The 1938 swings and his 1946 (early post-secret) have a lot of similarities...except for the way he releases the club and the post impact pivot.
I think Hogan was probably super long, but the super duper stiff shafts held back his distance. I have a couple of clubs with super duper stiff shafts that I experiment with. I can hit them just fine as far as straightness and trajectory, but they lose about 20-30 yards compared to my normal shafts I use.
But today's game is very bomb-n-gouge, hit up on the driver (another thing difficult to do with persimmon), etc.
3JACK