I think the forward game though has changed a hell of a lot, back in the miller days the backrowers were ball playing type guys and would take pressure of the halves etc, these days backrowers are pure workhorses, metre gainers and defenders.
I think currently our game is lacking in your quality 5/8 to be honest, hence the need for it to be compensated with a quality centre, Daley started as a centre and he had the brain vision and kicking and passing game to make it in the 5/8 position and he lost a bit of pace too due to his knees etc.
But i agree with what is said above the extra defense will hinder their attacking power, but I suppose time will tell, i personally think defensively at times Gaz struggles in the physical side of it and personally I would be running angles at him with your O'Donell's, SBW, Gallens etc.
I also think that in Gaz's case especially his backs outside him will struggle to see the ball at times, but that is just my opinion. To me both Lyon and Gas, look more dangerous when your 5/8 runs towards the lines and then fires the ball out to the centres to isolate the defenders, to me that is where they are lethal and the defense and extra responsibility of kicking and planning MAY hinder both players. IMO. For their sake I hope they do well just not when they play us.