Wow! Some of the pics with the heavier drafties are incredible! With all the sticker burrs I have to deal with here though, I can't imagine the time I would spend on manes and tails. I already spend a lot of time on them. I think they purposely roll in sticker patches. I join the "it's genetic" club though. I have some with pretty decent forelocks and then I have one mare with a mane so thick it almost sticks out side ways when I cut shorter, but her forelock looks like a dang water color brush. I've given up on it. It's just the way it is. She also has the thickest tail in my bunch. You would think she should have a good forelock. Nope!
It's not just the draft breeds. The Baroque breeds have the same problem. Between the sand spurs, cockleburs, beggar lice and beggar ticks that she picks up while riding, along with the sweet gum balls and twigs that they sweep up with their tales and collect in the manes from rolling in the pasture, I'm always pulling things out.
I've started to suspect that the "hitch hiking" seed plants secretly watch for the horses and then travel hundreds of feet to reach the horse if the horse doesn't get close enough on it's own.
That's one of the reasons I make no effort to keep the hair long on mine, but it just keeps growing in spite of the amount that gets pulled out whenever I groom them.
Folks, other than it appears to be the "look" that so many like (I've been threated when I mentioned cutting mine) it's really a lot of work keeping it nice, free of debris, unmated and without dreadlocks.
Of course this was about forelocks and that's the one thing that seldom has a problem.