I have long hair and it shocks me how people groom the manes and tails of horses. Not saying you are wrong but just that I do it differently and the same as I do my own and my grand children's long hair.
First I have a much admired Ostler tail brush. With wide spaced spikey plastic bristles. No. I do not use it and for a long time lent mine to a friend.
I use the stiffer of my two body brushes, more like my own classic Mason Pearson hair brush. I start at the ends the bottom of the hair, putting the brush on the hair about three inches up the tail and and holding the hair with my other hand just above the entrance point where I am brushing. This means that if the brush encounters a tangle, it pulls against my other hand and not on the skin of the horse. By starting near the tips of the hair any tangles come undon and you then move your hand up that chunk of tail and so on till you reach the top. Then you do the same with the next section of tail. Starting at the bottom and working gradually up.
Once you have worked through the whole tail like that (about four sections in all), then you can gently use the proper tail brush if you want. Again I start at the bottom of the tail and work up, but usually there is no resistance and no hair tears out. The tail brush is good if you want to rub some baby oil on your hands and brush it through the tail.
I am riding a big Iberian with a regal curly mane at the moment and I use the same care and the same technique on that and the forelock. But I dont use the tail brush on it. That is because when brushing the mane, I am pretty likey to brush her coat and neck under it too and prefer the body brush for that.
If she doesnt stand still even for a gentle brush, I do use my fingers and hands a lot while grooming. The horses are obliged to let me touch them and stroke them wherever I want - gently - no hurting. The horses I have ridden regularly and groomed regularly seem to like me doing it - But I treat each one as an individual - I use the brushes each one likes - Maisie whom I rode for year liked my American style brushes but Grace has a fine and sensitive skin and doesnt much - so I bought her something else.
But because I suffered so much from my Nanny hurting my hair when I was a child that I take a long time and great care over the mane and tail. Go very slow, very gently and very carefully. A brush that pulls out a lot of hair will hurt the horse. So pulling a mane is asking for trouble.