It is a funny argument. What is better? Big players or small players.
Here is my uneducated view.
Smaller players are generally fitter and quicker. In these days of limited interchange, you will see a lot more of the smaller player.
I like our players are getting smaller and trimmer.
Different strokes for different folks.
For instance, IMO, over the past few years our talls have been too big and our smalls to light.
I'd look at each player individually for instance Swan 3-5kg lighter just wouldn't work, we want Grundy to be a brute though I'd be interested to see how he goes 5kg lighter and I don't know whether he's body will allow it, but an extra 5kg on Oxley might be valuable because with his hands, footskills, smooth moves and slower pace I feel he might be best working as an inside mid.