Every time a club appoint a manager, you would assume that they believe that they've selected the best person for the challenge, within whatever confines exist.
Most of these decisions prove to be wrong. That's why most Championship managers were sacked during the course of last season for example.
Pearson was the last manager we appointed in the Championship and it took him 3.5 years over two spells to get us up. Before Pearson, I count that there were 7 previous appointments in the Championship that didn't get us promotion. Adams was the last one successful before Pearson.
Adams, O'Neill and Milne are the only ones I can see (within the last 50 years) that got us up at the first opportunity.
For Maresca to join this list he has the advantage of a massive budget in comparison to our rivals. However, I'd argue that he's handicapping us by insisting on a way of playing that requires him to exclude potentially excellent Championship players.
If it works, fine. I will be delighted to be shown that my fears were unfounded. I want him to succeed. But there is no way I'd have gambled this much on the financial future of the club.