I'm not refering to the outcomes of the new PC but rather how you need to set up Revan/Exile/Whoever else.
In KOTOR II lots of scenes chanced depending on how you answered Attons questions. A holocron on Korriban, What version of holo T-3 played etc etc.
Now multiply those by the number of possibilities you need to cover and you start to realise the absolute magnitude of the task.
I think it's 16 different outcomes, just for Revan/Exile LS/DS without adding in the fates of the NPC's.
Scenes are probably the most difficult thing of all, most costly too, so I think it's probably less than simple.