The problem with managing a team for some months is that the margins to work and evaluate things are limited. I've read many comments in this thread saying that it shouldn't be just about the points but also improving the style, players developing and stuff, which is kind of unfair.
A coach in his position can change, tweak, choose, motivate and add some details, but expecting an interim coach to build or develop something after taking over in mid season is fantasy.
We've been carrying the same problems when dictating in games for more than a decade, being either dull or too open if we take more risks, and it's not going to get fixed in some months. It can get masked under high levels of intensity, confidence, motivation with a World Cup ahead, added to the privilege of having energy in the tank 'thanks' to Ineos and Amorim. But expecting a solid evolution in any way is setting the bar too high.
Carrick's job should be about results which implies not leaving the tracks with experiments, adapting to the players and finding the quickest route to win games, keeping us well organized and boosting the mentioned variables, which he's doing brilliantly as he did in his previous stint.
But next season would represent a bigger challenge, trying to compete while introducing new elements in play, bedding new players in, dealing with a more congested calendar and some inevitable bumps in the road, and a sense of routine replacing the current enthusiasm, all under the pressures of this club. Teams will study what he does and will prepare for it, needing a response. Is he flexible enough, inventive? It's a huge job ahead and these next 5 months as interim trying to get results won't tell us much about his capabilities to lead us in the long run.
We had ETH getting a respectable 3rd position and a cup by being pragmatic in his first season, but when he started 'building' in his second season we were all over the place almost from start to finish. An underqualified coach getting results for some time doesn't suddenly become qualified for the job. Especially when it comes to winning the league which should be the goal for a team investing as much as we do, and even more now without any freak getting close to 100 points.
Obviously you can't quantify the quality of a coach nor predict the level of success at some specific place, but you can easily guess that someone like Enrique would get more from this team than Harry Redknapp or Taiwan U21's coach. Empty mantras like "there are no guarantees anywhere" and "everything is possible" sound nice for a Nike advert but make it look as if every choice is the same and give you the same percentages which is obviously false.
The club should aim for the best at every level and start the search of a top coach now while Carrick gets us the best possible results. There is nothing else to see here and we shouldn't be waiting for anything. Clubs are moving already going by reports and we should be doing the same.