Lots of interesting arguments and Shawn is right as usual about the Pressure..
Why the `Target Torque``?
First, It is an Engine Torque value, not a mast torque value.
Second: During Category A manoeuvres, following engine failure, different limits can be reached: the OEI can be limited by the Torque, the ITT or the NG.
In order to decrease the pilot workload following the engine failure at the decision point, test pilots have elected to use a single parameter to target . (So, you can focus your attention on only one gage, instead of monitoring 3)
At the targeted value, the engine parameters will not exceed any of the OEI limits and performances will be met. This target torque is based on a minimum spec engine performance
Whenever possible, (Ie: at Vtoss), If there is still some power available, the pilot can adjust the critical parameter (Torque, ITT or Ng) to the 2 ½ OEI limit.