That's some serious undervaluing of Mumford there. When Mumford doesn't play GWS are no where as good a side.Rubbish.
Nothing is less important than a ruckman.
Hawthorn? Never had anyone decent. The Bulldogs? They played a defender and forward as their rucks. Sydney? Had mediocre Tippett and a bunch of scrubs. The Giants? The have Mumford, who is a five packages of sausages with legs.
Who gives a s**t? Jacobs at 90% or Jacobs at 60% doesn't impact our ability to win.
Just because the Bulldogs used a different type of ruckman it doesn't mean they weren't a vital part of their premiership.
Our midfield relies on Jacobs, when he's not competitive in the middle we struggle.
You've conveniently cherry picked some ruckman and teams that you incorrectly think ruckman haven't played a crucial role at.
Ignoring those, how about Dean Cox and West Coast? Shaun Rehn and Adelaide? Darren Jolly at Sydney and Collingwood? Brad Ottens at Geelong, Clark Keating at Brisbane?
There are plenty of examples which show a good ruckman are a very important part of a successful side.