One of my biggest strategies to consider when migrating a large number of assets to production live AEM author instance is to enable/disable the workflow launchers.
Every time when a new asset is installed (via the package manager) or uploaded into AEM, the OOTB (out of the box) AEM workflow launchers will be triggered. During the operation/processing of these assets, the author instance will start consuming the CPU, and the environment may be slowed down, depending on the number of assets being processed at the time.
Since all your assets have already been processed by another AEM author environment, it would not make sense for each asset to again be processed; this will be a waste of usage of the CPU.
I am recommending that if a large amount of AEM DAM assets (that already been processed, zipped in a content package) are being installed via package manager into a production live environment, to inform or disable all authors to stop authoring within a time frame. Within the time frame, disable the workflow launchers and install the assets into the production AEM instance. Finally, re-enable the workflow launchers after all assets have been successfully installed.
To enable/disable workflow launchers, check out this article. How to enable/disable AEM Workflow Launchers