Flap 5
I believe you may be underestimating the workload with a diversion especially if one or both engines are giving cause for concern. The quickest option may be to return to base even if that isn't, strictly in terms of distance, the nearest option. The Boeing QRH (yes I know this is an Airbus) gives exactly that guidance.
Essentially, always look at the big picture and manage the situation accordingly. There may be competing elements eg a nearer unfamiliar diversion compared to a slightly further familiar one. Im NOT speculating regarding this particular incident though.
Of course, with the benefit of hindsight then one may sometimes realise another course of action may have been better and if that's what the TRE says in the sim debrief it must be true!