A design function that the Hawks have is a backup ( #3 ) hydraulic pump that is electrically driven, and is the same as the two primary pumps in flow/pressure capability, and this pump backs up the first stage pump pressure to the TR servo 1st stage, hence there is triple redundancy, source-wise for hydraulic pressure back at the TR servo.
As to your remark about doing it because its fun training is well taken here, as it was possible ( or at least used to be ) to depressurize both tail rotor servo stages by pulling the backup pump c/b, deselecting the #1 Primary servo and selecting the tail rotor LDI switch. . At least I think that was the sequence. It did succeed in depressurizing both stages as we intended. Anyhow, after that flight there was some reconsideration by the senior mechanical controls engineers, who were concerned that a switch back to a pressurized system with a bunch of pedal force being applied, would create a cable whiplash that might result in the cable coming off the intermediate cable attachment devices. Hence your point is very good advice.