It only helps us to have several good players vying for each position, and 7 is no different. Despite the trenchant views of a few, the role of a 7 is evolving, and really is becoming more how that player fits in with the balance of a backrow, pack and team. So we'll see different styles in different franchises. Ultimately, who plays more for the Wallabies will depend upon the coach, their game plan, and who else they have at their disposal in the pack especially. Not to mention the differing dynamic of substitutions - does a more pure fetcher give you more early or late?
IF Pocock gets back to full fitness, and you'd be mad to argue against someone so single-minded and meticulous about training, I'll be amazed if he isn't right in the mix. It'll always be hard to have good players like Hooper, Hodgson, Gill and Pocock "missing out" but look at the All Blacks in many positions. It's a good problem to have. If players leave because they feel they'll miss out, so be it. We should avoid trying to shoe-horn players in just to get them on the field.