Can I connect more than one TDM-capable iMac to my computer in TDM?
Yes, as long as each iMac you want to use in TDM is using a ThunderBolt connection and is connected directly to a ThunderBolt port on a supported computer. Keep in mind the limitation for the maximum amount of ThunderBolt displays a system can support as explained in Thunderbolt ports and displays: Frequently asked questions (FAQ). An iMac in TDM behaves like a ThunderBolt display.