Everything I'm doing is in Stonefalls. I may be silly, but I'm not that silly.
Also, I've gotten everything but weapons to drop multiple times for the set.

From what I understand, Set Weapons drop with Group Dungeon Bosses, along with other things. So, this results

https://forums.elderscrollsonline.com/en/discussion/300662/the-problem-with-weapon-drops-in-one-tamriel

I have found a decent amount of Set Weapons in odd drops here and there, like from Mobs or in Treasure Chests. However no where near the rate that I find Armors and Jewelry. But, based on the thread I linked above, your going to have a hard time finding weapons, especially the type you want and well, just hope the trait is not embarrassing but you need to take what you get there. I have gotten a couple of Sharpened Set Weapons, and a few Precise Weapons, but it is really hit or miss here.

This one time where I wished Monster items dropped in Weapons along with Shoulders and Helms. You could always go 5+5 Gear/Jewelry and then go farm a MA weapon....

Well I'm literally throwing away Red Mountain gear at this point. What many people do, and what I also do:

When you want to farm items from the set: Daen Seeth Dolmen, wait for spawn along with the other 10-20 people there at the time, kill everything, open the chest, run northeast to Shipwreck Strand and kill the overland boss. Don't worry, many people do the same pattern so
A) the dolmen and the boss are most of the times synchronized
B ) there are always people to help you drop both
I've stayed 1-2 hours when I'm bored between alt+tabing, watching twitch e.t.c. and I think I've collected most of the Red Mountain armor (impen, divines too) but I mostly sell them. The dolmen gives mainly jewelry. Most of the time the color is blue so you'll have to upgrade the good pieces. Also Red Mountain is not a quaranted drop, you are also dropping Sun and Shalk sets which are also worth decent amounts of money.

P.S. Now I read that you are mostly interested in weapons. Yes, this tactic works for weapons too, there is also a special one handed red mountain axe that drops from Shipwreck Strand boss and is unique (got it many times, nothing fancy). I think though that the only places where there are indeed high chances of dropping weapons, are public and group dungeons. If I where you, I would just solo *** Fungal Grotto, as Crow's Wood isn't that populated nor has it that many bosses.

I like where your head's at, Kaizo. I'll try that loop tonight. I already have all the jewelry in purple, but those tend to sell pretty well. So no complaints.

I farmed Red Mtn jewelry and weapons all weekend. It does drop in Crows Wood, but not often. I believe there are as many if not more bosses in Crows Wood as there are in Fungal Grotto (bear, wispmother, purple ghost, bat, spider, wraith). Having said that I also ran Fungal 1 on normal a few times and had better luck there. For the last weapon I needed, I finally gave up and camped the Golden Saint world boss for Madcaller's Blade. Not the best trait (infused) on Madcaller's Blade, but it'll do for now. There are 3 unique weapons as well: Madcaller's Blade (infused 1h sword), Netch-Hunter's Bow (decisive bow), and Rhorlak's War Axe (infused 2h axe).

ETA: Pretty sure weapons only drop on the final boss (or randomly on adds) in group dungeons.