Manly have not flooded the tackle area for a while now and prefer to dominate with stong contact more than numbers in the tackle, it's not as simple as saying "lets gang style tackle" to slow down the ruck like other teams if you lack the players and defensive techniques to do so.
For starters extras in the tackle means players have to involve themselves in more tackles(even if it is just third man flopping in) which increases defensive fatigue, a more thin set defensive line and the risk of even more penalties if your wrestling technique and peeling off the tackled player is not applied in a manner that is smooth and controlled.(meaning it looks so composed and dominant the ref rewards the controlled technique with more time to peel off the tackled player)
Mobile fit packs can defend in numbers consistently, more flexible in the wrestle and get back into a good defensive position faster, larger packs will struggle to sustain this level of intensity unless their own go forward is good and dominating field position.
Manly have to strike the right balance by improving numbers in the tackle at times but i don't see it as an all out adoption to save us.
Manly have dominated by winning the contact ???
They were torn apart on Friday even when making good contact, Keppie and Jake were left on the ground while Penrith played the ball as had no supporting defenders, thought this was pretty clear really and expected you as a TC, would have it as a Massive red flag that needs change ??
Similar to the finals series, where opposition teams with big players (yes big forwards like Manly), who used numbers so your reference of it's not that easy adding numbers...there is NO easy, it's a tough sport at NRL level, but it's better than getting gassed by your defence backpeddling, while the opposition plays the ball like a touch footy game.
In actual fact, you fatigue an attacker more by controlling and dominating while he struggles....
Also you have much longer to reset the defensive line, actually helping these defenders maintain energy.
Also this contributes to being able to follow up tackle after tackle, which as a player, gives everyone a lift across the field and maybe put pressure on that Perfect Penrith team who were allowed to play perfect as set the tempo.
The worst contribution to these bigger defenders tiring, is retreating backwards and having the opposition playing the ball 100mph.
The repeat penalties that concern you are also 3 times as obvious and easy to give away by that 1 - 2 man tackle as you are granted far more lattitude with a dominant tackle in numbers to ease off the tackle and have your defensive line in perfect position to go ahead.
I have a strong feel we will start seeing this type of defence vs Roosters Friday and also reckon it will work and add energy and control of the game....and hopefully the result