Shane,
Freo's requirement of high fitness levels is probably based around the requirements of Roly's version of Roo's game plan. You have to be able to run all day and mob tackle opponents so they can't score. In that scenario, it seems that high levels of skills were less of a factor compared to high levels of semi-skilled effort.
The game has evolved past this scenario where perhaps we haven't.
When the rules were changed to discourage negating game plans, the need for football skills has risen substantially and this is where we are failing. Your point on the difference between athletes and footballers is exactly the issue....and we seem to lack footballers and a game plan that supports them.
That said, in Bennel's case, I'd be taking that more conservative approach until he can at least be expected to run out a game. We are not there with him and maybe we will never get there.