IMO When Melbourne played well last year they were playing nothing like Sydney.
Melbourne played like Melbourne.
They always looked to attack, move the ball forward and play positive football.
They introduced "tempo football" and the result was what we saw from about the 3rd quarter onwards in the first game against St. Kilda.
"Tempo football" had nothing to do with better defensive skills. It's about controlling the "tempo" of the game. Melbourne's better defensive skills came from being accountable when they didn't have the ball.
That is, they continually looked to attack, but when the opposition had the ball they were accountable for their players, tackled hard and created immense pressure for opposition sides.
EDIT: In a way Melbourne were more like Sydney with their defensive pressure, but that's just about tackling hard and being accountable. Not "tempo football".