I tried something with Cherie's idea today. The old man ties pretty well, not perfect though so I need someone watching him. Had my neighbor over for a bit so this is what we tried.
Tied old man at the back of the barn, had neighbor watch him while I tacked up and left with greenie. She reported that he was perfect until she left his sight about 5 min later. (hiding in the barn keeping an eye one him) Then he started his usual 'meltdown,' spooking at random things and calling, getting worse over a few minutes. He calmed down she came back. As a note, he's fine tied without a person visible when he's being tacked up, but I've never pushed that for more then a minute.
I wonder if this is a confidence issue with old man. Donkey and mini are pretty much non existent on the totem pole, so when he loses both horse and human 'leaders' he gets scared? I guess that is why they say have three horses, I just hoped a donkey and mini would suffice!
Any ideas if this is indeed the case? Not that it definitely is, I could just be crazy.