Looking at the Chassis Wiring Installation
diagram for your coach it looks like coaches with the 1500-watt inverter have 3 12V Coach Deep Cycle Batteries while coaches without the inverter have only 2. I would expect these to be Group 31 size.
The upper tray has the Coach batteries and these should be Deep Cycle.
The lower tray has the Chassis batteries and these should be Starter Batteries, not Deep Cycle. According to the Built On Freightliner
info for your coach the OEM batteries are "Two 760 CCA @ 0oF (-18oC); maintenance-free" and I would expect them to be Group 31 size as well. Replacement batteries need to have at least a 760 CCA or higher.