Good ruckman will always be effective, arguably with less rotations and a faster paced game playing 2 ruckman may be harder to justify.How are ruckmen less effective now? We're two weeks removed from Nicnat tearing us a new one.
Thats especially true when your second ruckman gets smashed by an opposition key forward in the ruck (Ladhams V Allen from that WCE game), if your second ruck can comfortably beat the opposition make s**t ruck then you aren't getting the benefit you should from two rucks.
Ladhams as we know has freakish mobility and run for a ruckman so has what you'd want athletically if playing 2 rucks, but really needs to lift his game and make sure he is both giving as an advantage in the middle when competing against a part time ruck and is competitive up forward. Maybe a goal a game, crashing packs, bring the ball around and freeing up our other key forwards.