Salt separate from the rub

Any opinions on this?
http://amazingribs.com/recipes/rubs_pas ... _rubs.html
Basically you make up your rubs with no salt - and salt separately depending on the size and type of meat you are smoking.
Makes alot of sense to me - same rub might be used for both ribs and a pork butt, but you would need alot more salt for a pork butt due to its size - yet you may well use the same amount of rub on both due to the surface areas.
http://amazingribs.com/recipes/rubs_pas ... _rubs.html
Basically you make up your rubs with no salt - and salt separately depending on the size and type of meat you are smoking.
Makes alot of sense to me - same rub might be used for both ribs and a pork butt, but you would need alot more salt for a pork butt due to its size - yet you may well use the same amount of rub on both due to the surface areas.