Hahaha. Although that is only a logical comparison if months all came in multiples of 31, and more that one day in the month was commonly referred to by the same number. Dopey may well be a pedant, but his logic is impeccable. :)
And nor should you, Bromo Sapien. I liked it when I saw the early pics, I liked it more when I looked it up, and I love it on the wrist. It looks awesome on the fly; I'm delighted for you.
Warning: likely ignorance ahead.
If I might chip in a belated two penn'rth: I agree totally on the Tudor; although a bum like me would be humbled with gratitude to receive one, a guy with two Rolexes already is going to be hard pushed to look suitably excited. Like a guy with two loaded Mercedes trying to look happy that his wife got him a Skoda. Whether it's nice or not is almost immaterial; it's a step down in the same thing.
BUT, if you're going that far up in budget, what about the Explorer (1)? It's just as tough as the Milgauss (Gauss rating notwithstanding), it's a nice size at 39mm for someone used to 40mm watches, and the lack of bezel and simplicity of design is both as practical as the Milgauss, and more versatile/dressy if needed than either of your options, or either of his existing watches. What's more, it doesn't have a lightning second hand - possibly a little tacky/frivolous in an older man's eyes - and even more impressively, Frilly has one. And it's a touch cheaper I think.
As for the Explorer II, I guess you know he likes the style because he already chose two sporty Rolexes with a bezel. But apart from the practicalities of the bezel, maybe there's too much of a good thing? Something that little more discreet and clean might be nice as an alternative that he doesn't already have.
If non-Rolex is still an option, I have to say from IWC I'd be hankering after a Portuguese chronograph myself - within budget, on a strap for variety, and he hasn't got a chrono. And I just think it's pretty. But there are a million options in that price range as mentioned: any number of Speedies and alternatives already mentioned, or if you want to keep the budget down while keeping some integrity, maybe go German: something completely different but with individual/iconic design, like a Sinn if you wanted a pilot watch, or a Nomos Zurich is my personal $3k pin-up.
However, I've a feeling you've reached a place in your mind where it has to be a Rolex. And I think, as a 41 year old man, that even though I like the Milgauss, the Explorer 1 is a little more stylish and versatile for a man of substance. But that's maybe just me.