Like i rightly stated, I wont come to a conclusion on this matter. If he is a good coach, he will surely prove it in more than one season. Because some seasons are a fluke, being in the right spot at the right moment and luckily win a trophy. Manchester United almost did it last season but Tottenham took it away from them. Maresca should not be judge by one season performance, with time we will know if he is competent enough to lead the Chelsea team to more victories. But wining the Club World Cup and Conference league is quite a good performance for last season.
By applying the existing assessment, of course, it is not one season that needs to be seen, and it takes time to determine whether the coach meets or not, and Mareska has brought victory even though before coaching Chelsea and he managed to bring Leicester City as the Championship champion that I saw coaching at the club was not too long to determine the eligibility, and likewise when coaching Chelsea even though the results were good but in the coming season of course we can see and judge it.