I think Pollard should start, but can understand if Joe wants to use him as part of his 'bomb squad'. Fez was a bit underdone and Slipper looked cooked in some passages, but the scrum held up well, so he may start again. If Slipper does start again this week, I'd be tempted to rotate him with Bell at halftime.
All of the replacements did an excellent job of getting the Wallabies back into the game on Saturday, which might weirdly work against them when it comes to starting this week, so who knows what we'll see.