My sister was off school on the day they 'did' long division, by rote. Nobody ever explained to her the point of place value and she has never been able to understand arithmetic. If you show a child how a solution is reached, it doesn't matter if he forgets the exact forumula, he will be able to work it out.
I agree that all teachers need some training in child psychology and classroom skills, etc. Again, I have known some brilliant people who loved their subject and were quite unable to relate to children.
I chose to specialise in remedial teaching, and was asked by one young teacher if I did it because I couldn't get a better job. As I was much more highly qualified than she was, I was able to say that I actually liked teaching children with special needs, but many in the staffroom were contemptuous of 'my' children.
I think that history should be broadly chronological though. I have met many children who had done 'projects' with probationary teachers on The Romans, The Saxons, and The Tudors, but they had no idea of the time scale involved or even the order. Making models of Roman towns is fine, but they need to be able to see the broad sweep of British history, with invasion, integration, etc. and see how one period influenced the next.
Most people don't think that because they have had a tooth out, they could be a dentist, but I know a lot of people who have never been inside a classroom since they left school, but are bar-room experts on teaching.