We roach manes here, so easy to keep them cooled off, nice looking. I hate pulling reins and pulling out long hair too. Hair grows back fast if you don’t like it. Probably have a nice Mohawk in a couple months. Mine grow about an inch a month. They have very elegant necks when roached and need no braiding!
If you shorten, I advise scissors use over pulling. Pulling is painful, you may kill hairs pulling out quantities of hair. Seen it happen. And scissors are lots faster, easier on YOUR hands. Horse does not fuss, doesn’t care about scissor removal of mane. I would do shortening in 2 steps, to see if you like it halfway shorter or the 3-4 inch length… You can ALWAYS roach it.
We point the scissors straight up to cut. Working from the mane bottom, you can decide how short, then cut into mane at that length. Work up and down the neck doing mane shortening. Once you have excess length off, some cuts up into remaining hair get it thinned some, for a more natural look at the bottom, but neater. Not a chopped look.
I bet there are Utube videos showing how to shorten manes. They will show various methods.