I think you will find a player only has to look after himself and what he does on the pitch, with a manager he is respnsible for many things he has no power over which is a much harder task. The problem with Aqualani is he was just not cut out for the english game, he was far to weak and never had the mental strenghth to deal with what the Premier League throws at you, he just never improved at all or looked like he would adapt. Having said that he is not the first player with a decent reputation in another country to be found out as you only have to look Shevchenko, Crespoe and Ballack at Chelsea or Veron at United.
I too think Aqua may be revealed as being too weak for PL!
But my point is that if we want to do it the LFC Way, then it's just too early to sack him at this point!
Sack him if You want then, but let Roy be measured by the same criterion!
As You say: The task is much easier for the players than for the manager. This means we need to put more emphasis on the managers' development than on the players. In other words: Roy out ASAP!