Some breeds don't need their tails docked at all, but most wool breeds generally do. I'm pretty sure your girls are too old.
The problem with long tails is that muck gets matted into the wool under the tail and they can get fly strike. That being said, I have a friend who doesn't approve of tail docking and she's never had a problem from it. She (like you, I think) has a small enough flock that she would notice if any of them were having a problem with a dirty backside.
i had a ewe lamb get fly strike, not a pretty mess. Disgusting, smelly, and a bunch of creepy crawlies that i kept thinking were gonna get on me and eat my skin. I'm not sure how she ended up with it, i had docked her tail and 2 days later there were maggots all over her rear digging their way around her tail bone burrowing deeper into her skin; some made their way into her vulva. Nasty.
you could probably get a vet to dock them foryou. I think @Southern by choice had her vet dock one of her sheep's tails?