1. As per your MSP License, say you have 2000 Assets.
2. Say you have 2 sites, with 2 different RAE installed, each with a license of 2000 Assets.
3. Summing up above (step 2), it will come to 4000 assets in total. But when the assets are pushed to MSP, the first 2000 assets will only be licensed.
So the above Asset Categorization from RAE to SDP-MSP works based on, a "First Come, First serve" basis.