I tend to over think stuff as well.
For your needs, you will not see any appreciable difference. Non-emissions diesels and ULSD are really bomb-proof. I have several as well. A T444E in an International truck, and several Yanmar 3 cyl IDI engines.
For your old gas engines, any HDEO that doesn't thin out to water with the expected oil temps will be fantastic.
I'm in agreement that a non-detergent oil should really never be used, there is no advantage. I have a 1954 Farmall Super M and it get Rotella T4, and must have a million hours on it....no way to tell. Just keeps running.