As you should be, he hasn't played a game yet! But there is still a place for the big units, especially if you can afford to run them in short stints. The smaller and more mobile others get, the easier it is to run over them.
I'd say gone are the days of Lolo/Hass like players playing 70-80, but you'd still want both those guys in your side on playing ability, not so much off field with Hass.
If everyone is doing the mobile fit forward thing that is who all those guys get used to defending too.
Suddenly the 125kg straight runner might be no chance of breaking the line but will certainly bend it and the extra 10cm and 20kg he has to throw around in the tackle make getting an arm free a lot easier...
We lack a lot of aggressive running from our edge players so I'm happy to pick it up in the middle for short stints.