Don't agree. I agree with Hughes, our focus should be third. Although likely impossible, it is still the highest possible place we can finish (barring financial meltdown from the Old Firm ). Any aim less would be a worry for me, as we are selling ourselves way shorter than the max. Might as well aim for 75% performance from now till the end of the season.
Note though, this does not mean we should be unhappy if we fail to reach our maximum target. But I would be very upset if McGhee or the players were happy just to be in the top six like you are making out from this position.