Duplicate SIDs generally are not an issue in modern Windows environments, especially on domain-joined systems because Microsoft addressed this years ago, and in practice they do not cause the kinds of issues you are describing. It is much more likely something related to the update itself or the cloning process rather than SID duplication.
Also, tools like NewSID are long deprecated and Microsoft no longer recommends changing SIDs that way, ever! If you did, I would start with a clean install of that system. The only supported approach now is Sysprep before making an image if you truly need a generalized system. Personally, I am an Autopilot type of guy at this point in my career.
If you really are cloning machines after they have already been fully configured and joined to the domain, you really are creating more problems than you are solving.
No offense intended, but the number of scattered questions and assumptions among your posts is a bit strange. It may help to step back and clearly describe the environment, what you are trying to accomplish, and what the actual symptoms are. That will make it much easier for others here to help you troubleshoot the real issue rather than chasing things like SID duplication, why your default printers change, what the best practice is for shared administrator accounts, etc. which are all very unlikely to be the root cause for what you are trying to accomplish.
