About the previous sacked coaches based on the picture, I think Tottenham was too quick to make the decision to sack them. Because anyway, as far as I remember when some of these managers did not have as bad results as this time which is very close to the relegation zone. Therefore, Tottenham's sacking of several previous coaches was not theright decision because it seemed to happen in a hurry. But for now, it was the right time for Tottenham to fire Postecoglou. Because anyway, it seems that Tottenham have never fallen too deep like what happened at this moment and thus, sacking Postecoglou I think is the right decision because if not, maybe Tottenham will fall even deeper maybe to be in the relegation zone.
Their boss Daniel Levy is a man of business, and he chases profit for his club as most as possible by selling their star players in many years with expensive transfer prices. He does not have enough patience to wait for titles from Mourinho and Conte even they are good coaches with their tested capability. Hiring Postecoglu in the last season, is a doubtful decision for their club future.
Postecoglu and Tottenham began the last season very impressively but their decrease in later of past season, and its continuation in this season, are all enough to show incapability of Postecoglu at a club like Tottenham. This time, Daniel Levy made his good decision to sack a head coach for Tottenham Hotspur after more than half of disappointed season.