You obviously have never done a preformance run for maintenance either. The difference between two engines with different Tq is more than likely the condition of the engine. It's a lot easier to see a engine loosening power on a twin as you can see the them together as you run them. This is where trend monitoring comes into play.
When you fly what do you set too.
You don't set to N1. However this is the first thing as an engineer we look for , this tells us what the condition of the engine is. For a set Tq ,np , wf we should have a N1 in a region if it's out we ethier have a sad or good engine.
Tq is in the power section in the prop reduction gearbox. Helical gears that allow the disc to move. The more Tq the more it moves. It will not vary the Np when it's in the governed range. Hence you set Np then add power Tq will rise Np will say at the set range. N1 will rise itt wf will rise. Np will stay the same.
If the engine is running to 96% and is itt limited it's a sign of a poor gap seal at the compressor turbine. Not Tq limited