My niece is a primary school teacher, and used my son as a case study. She went into his problems deeper than she needed to as my son is her cousin and she therefore had a further interest than the text book, that his complex issues do not appear in.
I Think more that teachers are taught to look out for general signs of learning problems, although may suggest to a parent what they think it may be. But not being medically trained they can not diagnose, only suggest further investigation via the medical profession. However many over step the mark regularly and with disastrous results.
So basically part of their training is to note a child who behaves outside of the box and seek medical intervention, not to diagnose a condition themselves.
Classic example practically every teacher my son has had, and he has had few, has stated to me categorically (and these are English ones as well as Scottish) that my son is autistic despite many school doctors and consultants stating categorically he is most definitely is not. Even when armed with this information the school and teachers have still continued down the autism route, refusing to listen to me or consultants with the result he has had the wrong treatment for years, and I have been branded a parent in denial
So when the teachers suddenly realised it was not autism they branded him a badly behaved boy and me a parent who can't cope

Why? Because he didn't fit their text books!
My BIL is also dyslexic, the number version, and is now a director of a very well known building company up here.
I believe the several different types of dyslexia intermingle because of a lack of self esteem and confidence. Also the supposed co-ordination problems. If your told your stupid often enough you eventually believe it, and that includes all the negative comments written on work like 'must try harder'.
My accountant friend struggled with maths at school, in the bottom set the lot. She actually had no problems with numeracy but a self esteem and confidence problem, and a bullying teacher calling her lazy and stupid!
Just as a point she told me recently after her parents took her to be assessed privately she was recommended to use small building blocks and build using both hands at once...basically making both sides of the brain to work at once, just as brain gym does. She spent hours and hours doing this.
She hates Lego now
