All the drive vendors who matches the same capacity may not have the same size. Drive coercion is a storage controller property to force (coerced) the drive capacity to the minimal size supported by the drive in the disk group.
References
https://www.thomas-krenn.com/de/wiki/MegaRAID_Glossar
https://www.intel.in/content/www/in/en/support/articles/000007774/server-products/raid-products.html