Paxton sells their access controllers as a single door controller, in a metal enclosure with power supply.  This allows each controller to be installed near the door or in a nearby wiring closet.  In the case of an installation where there is a high density of controllers in one place it might be desirable to place multiple controllers in a single enclosure.   Paxton does not sell a multi-unit enclosure but there are third party products available for 8+ doors from the following vendors.  These are custom solutions requiring configuration to ensure correct power, mounting backplate, etc.

ALTRONIX TROVE2