RDP will take a session from the main station and create another user using a pre-existing Computer layer. So many RDP sessions will put a lot of pressure on the linked station. 

Specification Chart (For Tablet)

Desktop Specification

CPU i3, 8GB Ram                                                                        | 3 Tablets

(CPU i3 or higher, Ram 16GB) or (Separate Desktop PC).   | 4-6 Tablets

Memory Consumption

Windows + 4Soft       | ~3-4 GB

MS SQL                       |~ 2 GB

Jump RDP     |~ 1 GB / 1 Tablet Session

Lowest Ipad Model Supported: IOS 12 , 3rd Generation up