In most places, where buses are involved, the Speedy Boarders are put on the first bus, quite often on their own. The exact implementation lies beyond the direct control of easy as it is down to the handling agent, but this is certainly how they (and the crew) would like it done.
Allocated seating is something that I guess the airline is continually evaluating - it doesn't need to cost more at all: the question as far as the airline is concerned is whether the benefit (passengers like it) outweighs the tactical cost (almost certainly slower boarding, no more speedy boarding).