I'd never bring just one pair of shoes. I got a terrible blister a few trips ago, while wearing shoes that I could have sworn were extremely well broken-in. So glad I had an alternate pair with me. What's comfortable at home, running around town, is totally different than WDW -- you can log 8 to 10 miles a day, easy.
Plus, if it rains heavily, it's nice to have two pairs, so you don't have to put soaking-wet shoes back on the next morning.
I recommend at least two pairs of shoes for everyone, including your kids.