Or maybe it's one of those Texas things.  More always means better in Texas.  

Those who can make you believe absurdities can make you commit atrocities. -Voltaire

the extra waiters you saw supplying knives and spoons and all that were most likely bussers. they are ppl who clean off tables when ppl leave, who set up the silverware, who help to set up service for food at a table...they're sort of "waiters in training" or sometimes they work that job as an extra. it's the lowest rung of the wait staff, reflected in the smaller percentage of tips they receive.

in addition to a set percentage, waiters will tip bussers who do a good job for them.