These comments are hysterical! Rick Steves, Anthony Bourdain, and Giada di Laurentis!

Truly, I would let your DH do whatever he likes. I always hate to be on the receiving end of the stare down when one's DH spills something on the only other pair of slacks he brought because I told him he would only need a couple pairs.

I also think three pairs for him is more than adequate, especially as you will have access to washing facilities. The thing is, you can wear a pair of jeans a few times before they need to be washed :)