I think weaning them together is great. Sometimes it's nice if you can remove foals and moms from earshot of each other, but that's not always practical, and many times, weaning goes surprisingly easy, if they are growing up and growing independent naturally ;~D
Thanks for your help. as you know this is a newbie for me and I want to do it in a way that causes as less stress to mare and foals as possible.
We do not have a field that is totally out of earshot, but the two we can use are not on the same fence line which I think would be the way to go.
The colts are already pretty independent in their behaviour, they do not stay at their moms sides at all, but run together and sleep together away from their moms. When we have them in the round pen, they do not seem anxious to get back.
Like I have said, they are already drinking water and having feed and hay by themselves to make sure they get it and that they become used to that being available at certain times of the day. : )