could any of you enlighten me how this practice of recognizing and determining the correct point for taking control by the non-controlling pilot is practiced in the simulator in a realistic manner?
In addition, what proportion of a pilot's annual simulator time might be spent in practicing these 'Its time to take over' scenarios?
Well, now, there you have put your finger on it, Mechta. It would be true to say that EVERY MINUTE in the simulator, the Pilot Monitoring (as the current phrase has it) is checking he/she is happy with what is going on. Whether it is mishandling, incorrect response to malfunctions, failure to follow a clearance - whatever - the PM is expected to voice his concerns, or takeover, depending on severity and timescale. It would be dangerous to take over if you are wrong, so it needs at least a moment's thought.
So, it is not "A Situation" that needs practicing, it is a whole - what shall I say? - job description.
We can't define a point for intervention. It is a matter of judgement. If that judgement is not clear cut, it may take time to decide to intervene.
I don't think we can ever define appropriate action for every scenario. That is, we have drills for predictable events or failures. But as far as is humanly possible, things are designed not to go wrong, so when they do it needs analysis, not impulse.
And time for analysis may be very short.