But whether it's Nebuchadnezzer's rulership personally or the national rulership, it's still a head of gold. So the same argument applies against seeing it that way from God's point of view.
I agree that historically it appears to be true what you say about how they treated God's people, but all of those nations suppressed their absolute freedom to worship as God intended. So I don't think the whole thing is about how hostile they were on a scale of 1-10 against God's people, but rather the quality of human rulership in relative terms only.
Surely no human government is GOLD from God's POV so this all has to be relative in some way. Don't you think?