I have to agree with him. If you have many variations of your main sport, you are bound to win more medals.
I don’t necessarily agree.
I think it’s easy to say “well, swimming has a ton of chances to win medals”. But the other side of the coin is that if you compete for all those medals you are usually going up against people who only compete in 1 or 2 events so you are going to have to have much better endurance to beat them. Sometimes swimming in meets that are 20 minutes apart against people who are fresh.
Also you’re dividing your training between all those different events while they are focusing on one or 2.
It’s hard to compare across events in any case, but I think people who downplay Phelps’ achievement don’t take that into consideration.