Except for the fact that the Winter Soldier killed Howard and Maria when Tony was only seventeen. They probably weren't going to have anymore kids, but it was possible that twenty-year old Tony might have ended up with a baby brother or sister ... possible.

"He was." It's easier to talk about Tony, just as long as they kept moving away from ages and times of death. "According to the media he was a prodigy." Also according to Tony, but no one should ever listen to Tony when he starts bragging about himself.