Well with the way you are sounding it's seem Enzo is some of kind of magician that will magically make everything about Chelsea work perfectly, well there is no doubt that the management of Chelsea are found of sacking coaches but I think we all can agree that it will definitely take more time to rebuild this Chelsea team than just a year.
A year is just short a time to get a team to becoming very strong and a perfect contender across all European league competition but this fact appears to be understood by on a little fee amongst the crowd of fans and sometimes even the management, I stand to be corrected, or may the managements see much more with a coach and that's why they get them sacked almost immediately they are not getting what their expectations were from a particular coach probably after a period of a season and in some cases two seasons.
The case of Chelsea have become too frequent that it may even take them more time to build back the team to stability because firstly they will have to keep scouting for a coach that may perfectly fit in to their policies and terms of contract long enough and secondly they will now need the time to be patient long enough with the coach to be able to build the team as much as he can to the point where they will be as productive bas expected of them. the main purpose a s essence of all of this is in the fact that Chelsea management wants to get results and want the team back to winning ways but at some point I looks like they are not going about it the right way so they are having to suffer continues change of Coach till they will get it right.
Amongst the fans, it normal to keep expectations very high especially when a new coach who's got some good reputation takes over the management of the team a d that's the case between Chelsea and Enzo. He's got some good reputation with his former team who isn't considered as good bas Chelsea so it's normal to believe that in a good team he will do much better but then realistically the expectations should be within what is achievable and not making magical expectations.