Growing winter coat

I have my horses for 3 years (almost). For the 1st winter my qh growth lots of coat (she was 2 yo back then). After I moved her to my own place she didn't grow as much last year and quite little this year. What could be a reason for that? On other hand my paint grows quite a lot of fur (can't even tell more or less than previous years). She doesn't look like she's cold and in fact she's not a fan of blankets (unlike my paint).

I wonder if they are like the wholly caterpillar and put on a heavier coat if the winter is going to bad. Sort of like a horsey weather predictor almanac

Maybe its the breed or the metabolism of the different horses

Well... She's pretty fat. Could that be a reason? However paint is not on skinny side either (although she's much more narrow than qh). May be good shelter (with wind-breaker) and trees around (so its not that windy) helps? No idea...

It seems to have a lot to do with age of the horse...around here...the old farts will wooly up early

At what point should a horse have a good looking winter coat? I'm new to this, and am fretting over Blaze's coat, if its long enough and when I should start to worry. He wasn't blanketed all last winter but would be brought inside in terrible weather. His feed has also changed since I've had him and I'm trying to fatten him up a little.

Yeah, I noticed more old horses getting more wooly quicker, hehe! I think maybe where she is could cause it? Like, she needs more warmth? Hmm, I'm not sure. LOL Vida- maybe that's what it is!