The good big guy...etc quote is an oft used boxing quote. In recent years rugby has become a bit size obsessive. Wingers are a case in point. But there's still only one Jonah Lomu. But the evolution from the Rob Egerton 1991 winger prototype to the 2015 Julian Savea model has been an appropriate one. Size, power, speed all matter in that position. The same evolution has happened in the NRL.
However, the "physicality" term is now a bit over used and over analysed across the spectrum of positions at the expense of attributes like agility, vision and guile. Not that physicality isn't important, it is just out of kilter with the other skills required. Pick a big team and it doesn't guarantee success...think South Africa v Japan.
Halves are getting bigger in both codes but I don't see many Mike Phillips prototypes in world rugby or the NRL. Maybe that's why they're halves?