This is an interesting consideration with expedition/adventure team size. There is a tradeoff with redundancy (someone will have a spare x) that keeps the group moving, and the increasing liklihood of somone haveing a problem at any given time. You need to minimize the latter, b/c not just its slower/more comlex, but it eliminates the redundancy (your 1 spare is now used gone, but larger group still to worry about, etc). This is often why an ideal team size is 2, not 8-10.