Poch ran out of steam, but I don't see how people can judge him. The book - perhaps an error of judgement - I think the reason Poch ran out of steam, wasn't just due to all the stadium problems and the limited budget.
I think it was the old Spurs downfall - trying to be competitive whilst playing attractive football.
To that extent he is an example of a Spurs tragic figure. A lot of managers have found the idealistic side of Spurs in conflict with the demand for results. The only managers that have been able to combine both were Rowe, Nicholson, and the General - although Burks was given time. Rowe ended up having a nervous breakdown and only Bill Nick survived it all intact - deep down he was a bit of a contradiction, negative and dour in some ways as a person but deep down he was steeped in the Spurs tradition of winning in style, and he delivered.
Mourinho will win things, it will be by playing calculated non-attractive football - I think a lot of Spurs fans now recognise this is a compromise that has to be made once in a while, as with George Graham.