OMG.. He wants them in foster care ? Why not with their mother ?
Step back and take a breath. What you are suggesting did not come from Dad, but from Dr. B--according to Mom's attorney. We know nothing whatsoever of the context in which this was discussed. We do know--as of yesterday--that the GAL says that Dr. B opposes the children returning to their mother's custody.
The GAL, in his response, was pretty careful not to go throwing a lot of details around in a public record (just by contrast to Mom's attorney who seems to delight in playing to the crowd rather than the court), however, he did allude to emerging concerns coming from conversation with the kids. Now--do I think that this means that the kids have stopped wanting to see/live with Mom? No. But do I believe that their recent removal and change has resulted in some different adults listening to them in different ways, and perhaps giving them some new sets of permissions to see and share differently.
I too worry about the suggestion that the children may need to be separated, but not because I think it would move forward in the way that Mom's attorney has described, or because I believe that Dad doesn't really WANT all of them. I worry because to me it signals that at a minimum they are reinforcing harmful patterns in one another. And, at a maximum--well I don't like to go there.