Just on the leading up to the ball point, forwards need certain attributes to make this work. They need good timing / instincts, enough acceleration to create separation, either enough speed to keep space or strength to hold it, and good hands.
I'm not sure we've got too many of those blokes in the forward line (or anywhere). Tabs can run, but he's unlikely to beat someone on the burst, or hold his ground. I reckon his best go is to run around a lot and hope someone kicks it to him. It's not a lot to hang your hat on, but it's better than we've got.
I've never seen Kersten create much space, and is too small to hold his ground. Seems to have decent instincts and a good set of hands though.
The only people on our list I'd back to be able to lead at the ball are McCarthy (good instincts, decent burst speed - but he's been horrible out of form) and Ballas, who doesn't quite have the burst speed anymore, but knows exactly when to deliver a sneaky whack to the defenders guts and run at the ball.
So I'm not sure a traditional (re: not used by anyone anymore) approach of exclusively leading at the ball would work with our personnel. It's also impossible unless you move the ball quickly from defence, which we only manage to pull off in patches.
But for what it's worth, I'm not sure why you'd play both Kersten and McCarthy. If Cammac is back, give Kersten a spell and let Tabs run around a bit.