I think you're missing the point - what's the point of this last week before pre-season if not to get overexcited and make silly goals? We're not the board or managers, we can demand a top of the league finish!
And in seriousness, each player should be thinking like that, or else they are not showing the right sort of ambition or self belief necessary for a competitive sport.
I don't think us reaching 4th and Arsenal being 5th is that unbelievable (unlikely perhaps, but not unbelievable), it nearly happened a couple of years ago didn't it? In fact, that season I believe (I'm sure you'll correct me if I'm wrong) it was the mighty lilywhites at the top of the table at Christmas! Not such a "silly unachievable goal" after all?