The discussion is going off topic, but... :) I wouldn't agree. I don't keep halters on my horses. Never did except for the 1st month (they came wild and need some time to get used to people). As long as they accepted me I took halters off. It takes me 30 secs to put halter on, and if they get loose they can run away with halter as far as they can do without the halter. And with their habit of putting nose everywhere the halter can get caught and even break-away one can still can bring some damage. As for rope halters it's plain dangerous to leave them on in field.
Dinglehead, I think your 1st horse is very nice looking baby. 2nd one is definitely underweight, but as you said she's rescue and on old side, so it may take you a while to bring up the weight on her. But she's very cute too.