Do the math...
The FCI for 4 crew TA flights is IMHO only an official plan for destinations where they CAN NOT layover (e.g. Kiev)
If you do the rough math on this one:
A skipper costs the company minimum about 70000 DHS per month, an FO 55000. That is cost to the company, not what you get in your salary ( salary + housing + medical + training + provident + ...)
If we look at the turn around where this might happen, they would have a minimum block time of around 11 hours, there and back. Roughly 330 extra crew hours required per month for this to happen, so minimum 4 extra crews required.This would cost the company (70K + 55K) x 4 = 500000 DHS per month.
For 500K per month, they can spend around 16500DHS per night on layover costs, or for a main fleet crew around 900DHS per person per night for the layover.
Looking at the hotel prices and allowances we get, I would say that in general EK doesn't spend that much per crew on a layover, so bottom-line it would be cheaper to layover compared to scheduling a 4 crew TA.
I realise this is some rough math with quite a few estimates in there, but you can't argue that there is no cost benefit, and isn't that exactly what drives this company nowadays?