I know Farke has been mentioned as a name who was given time to turn things around where he built an identity.
Here are another few:-
Jokanovic did really well first season but missed out in playoff semi finals. First 4-5 months at Fulham last season were terrible, and some fans were calling for his head (he never got the players he wanted in). Come January he brought those players in and Fulham surged up the table and got promoted, they had an identity.
Lee Johnson joined Bristol City three years ago, kept them up comfortably for his first half season. His first full season with Tammy firing in the goals they only just survived getting relegated. Bristol City kept the faith, and the following season Bristol City started strong. They were in the top 8 for much of the season, and reached the semi finals of the League Cup. They then collapsed and finished the season terribly, many fans were calling for Johnson to leave. The start of this season Bristol City started poorly again, they were languishing in the bottom half of the table and again there were calls for Johnsons head. Here now in February Bristol City have won (9 games I think) in a row and are verging in on the playoffs again. They had an identity.
David Wagner less so, he came in did what was expected and in his first summer bought in 15 players (according to Wikipedia) and guess what they got promoted. But again he built his team.
Of course none of those clubs are a club the size of our own, where there is less patience and more expectation. However we are now a club who has underachieved year after year for arguably the past 9-10 years. Something needs to change drastically and I feel we need to give Smith time as others have supported too.