There's more than a few old school routines that put BB Curls first. While it's hard to argue w. old Reg and I can see curls as a decent upper body warm-up, I would imagine putting them first would not be beneficial for the work ahead in the rows and deadlift.
His workouts almost always put curls first, as do several others as you note. That said, I believe he recommended 3-5 minute rest periods, so recuperation was not as big a deal as on faster paced routines. YMMV, but for me DL does not impact arms much, rowing does though. Interesting observation though.