Cordy doesn't really mark much as a forward either, but I'd back both of them to bring the ball to ground consistently for a decent crumber. Both are then good for their size once the ball hits the ground. I'd say Cordy is slightly better once the ball hits the ground, but he's not as good at backing up in the ruck.If you can't mark overhead as a big fwd not sure how that is competent.
For me, Boyd's versatility substantially increases his worth. Imagine if English went down to injury early in a big game like Roughy did in the 16 prelim. If our other key position players were schache, Cordy, naughton, young and Adams, we'd be in deep s**t. None of them can ruck. Throw Boyd into that mix though and we're ok.