Upon migrating the same logs to a different location and forwarding seperately from those two locations to two independent indexer , there is generation of duplicate events.
It makes sense to me that the data was duplicated.
As I understand your description of the situation:
File copy 1 -> read by forwarder A -> sent to indexer A.
File copy 2 -> read by forwarder B -> sent to indexer B.
How would any of the "A" instances know that the second file copy or the "B" instances even existed? If these copies and instances are truly independent, there is no way to avoid the duplication.
Perhaps I don't understand the question properly.