I don't disagree. But just because he's never been tested at that level before doesn't mean he won't pass the test when it's put to him. They could have a season like Spurs last year with a team that fails to gel and a manager who eventually started to look out of his depth. But equally... Rodgers might just be a better manager than AVB and he might prove himself this year by stepping up a level.
Obviously I don't want it to happen that way - Liverpool's success makes our success more difficult. But unfortunately Rodgers has impressed me so far, and he's not really given any sign (in my view) that he's hit his ceiling yet.
Also he's got a defined patter/system of play that's already been implemented and working. Assuming he has specific plans for where the new players fit into that then it will be a lot easier for them to slot into something that's already in operation.