Sammy has been trying to pass on Sammy's zombie knowledge onto Yasmeen, but alas she doesn't listen and just calls Sammy a dork
It won't be Sammy's fault when she dies as a result of zombies
4-5 is the ideal number of people
Have too many people and you have to carry more supplies (i.e. Ammo, Food, First Aid, Water, etc.), thus slowing you down, plus if something happens to a person then that will slow you down too