I don't know what was going on when I did it, but it seemed way easier to me than expected. My daughter warned me that it was super hard, but I did it the first time despite making my way to the fuel cell before visiting the reaper and having to find the reaper before making a round trip. I didn't find the magitek units particularly hard to avoid, and I only got into one other fight after the mandatory one. Maybe I was just lucky, but it seemed to me that if you paid attention to where everyone was facing and intelligently utilized the walls and rubble to avoid LOS with the units, you could avoid 90% of the fighting. I ended the scenario with six unused medkits.