Does swimming "inform" muscle growth? A dryland/weights q.

Ok, so here's the thing. I know well and good by now that swimming does not really build substantial muscle mass. If there was any doubt, all you'd have to do is look at someone like Mark Spitz- an Olympic champion who clearly would have swam enough to see any of the benefits swimming had to offer: www.tierraunica.com/.../6a00e551962103883300e55419aa128834-800wi Compare that though to today's champions: 4.bp.blogspot.com/.../ryanlochte.jpg www.popstarsplus.com/.../MichaelPhelpsPicture.jpg Obviously huge by comparison. Now, the simple answer might be "weights. These guys do a lot more dryland than they did back in the day". But here's the thing- in all my years of lifting, I have never once seen anyone lifting beside me at the gym built like these guys. The people I see are jacked, sure, but proportioned very differently- and I've seen hundreds if not thousands of guys who were serious about weights! The only time I *did* see, in person, people who looked like the pics above were, no big surprise, the guys on the local college's swim team. So I contacted the coach and she was kind enough to send me their dryland routine- and guess what? Incline bench, deadlifts, flys, laterals, etc. etc. etc. In other words, the same identical program that countless weightlifters use every day. There was no magic formula to it. So this left me really confused. Swimming alone doesn't build this sort of physique. But weights alone don't do it either. Is their some sort of magic I'm missing here? Does something happen with the combination of the two that results in this type of build? Please chime in if you have a lot of dryland experience or, even more so, if you're actually built like this from doing these things! Thanks so much for your help, BB