Real flights have those things in some numbers and a model probably ought to attempt to account for them, since, as you noted in a separate post I can’t seem to find now, they’ll affect the model negatively. The goal isn’t to find the best number of late people and wheelchairs. It’s to be able to board real flights as quickly as possible and every real flight I’ve ever seen, except the flight I took shortly after 9/11, has had some number of strollers, wheelchairs, or what have you.