Without being rude, have you ever worked in, or even been in during severe weather, a railway Control Room? During such periods the phone is ringing constantly, such that as soon as one call has been answered, and the matter dealt with, than another call comes in, which also needs to be dealt with; And so on and so forth. Those with access to the Control Centre Incident Log will know just how much pressure there was on the staff that day, something that was mentioned in the Carmont report. That is the reality; Controllers are not sitting around drinking tea or reading the paper on days like that.
Please also bear in mind that SICC deals with the whole of Scotland with a limited number of staff.
From where? It has been tried, during my time in Control, and (through no fault of the people involved) can be as much of a hindrance as a help, because they will not be familiar with Control basics such as areas of responsibility, both in Control and outside, logging and fault recording systems, phone operations; And that is if there are even spare desks for them to sit at in the first place.