Differences and similarities between Muggle cops and Aurors which are not mentioned in the lesson -
** Something which is not addressed in the lesson is the matter of those who are 'employed' as policemen or Aurors are given assignments by the Powers-That-Be.
Many of those who sign up to be policemen and -women and Aurors have, when they sign up, someone in charge who is honorable and eleemosynary in their character. The system, as far as they can tell, works. They would not sign up if there was apparent madness or 'evil' inherent in the system which they are joining.
But things change. Depending upon the consciousness of those in charge, and just what their agendas are, the policemen and Aurors might be given assignments which are counter to their choice of being of service to the 'entirety' of those who cannot defend themselves. They can, according to those in 'charge' of them, become those who are criminal and committing crimes. This is quite obviously shown in the HP books, when Pius Thicknesse takes charge of the Ministry of Magic but it is also alluded to when Cornelius Fudge is Minister of Magic -- and Bartemius Crouch Jr is 'killed' (in addition to other outrages that the Ministry decrees are needed).
So the policemen and -women, and the Aurors, who wish to be of service to the general populace, to act as guardians, are basically being told what to do by someone who is rather insane (or controlled by someone who is insane....). There is often no recourse for them, but to appear to be abiding by the changed rules (they would never have signed up if those rules had been in place) or to go rogue.
** I think that it would be good to have more Aurors out in the field. As long as there are those who are of the mind-set of Moldy Voldy and Death Eaters and that ilk, there will be those who are prone to prey upon the innocent. I'd rather not think of it as preparing for another War but as preventive measures to keep it from happening. After all, bullies are rather cowards. They may believe their own lies, and be able to persuade others that their lies are 'true', but, in essence, they have no real truth and they push others in front of themselves to take the brunt of who gets killed first (cannon fodder). The training is a good thing to continue. Even if the people end up not quite making the grade to become an Auror, for example physical weaknesses showing up when stressed, they still have the training with which to be effective, and the mind set which caused them to wish to be an Auror in the first place. They will, if needed, join up with the official Aurors ... quite effectively I imagine.
"You have the inborn natural right to remain silent. Don't think about it, don't talk about it, shuush ....... STILL." ~ Xaris