Earlier quoted context omitted.
The question makes perfect sense to me. I don't know the ideal number of seeds on a bun off hand, and don't expect the executive does either. Do you know it?
Why would me knowing it matter? So shareholders are paying for the exec, and they are paying for the consultant who is doing the exec's job? If you work as an exec at MCD, working this out is the kind of thing that you should know. It is the reason why you are being paid money to be there.
The job of the executive isn't to know the answer to every question. Their job is to make sure questions get answered. There are an infinite number of ways you can do this and hiring a consultant is a valid option.