I do it that way occasionally, usually when shit is hitting the fan, but then I alternate the intensity of workout 1 and workout 2 from week to week - so, for example...
squat 5/3/1, bench 5/3/1...deadlift @70-80%, press 70-80% (week 1)
squat 70-80%, bench 70-80%...deadlift 5/3/1, press 5/3/1 (week 2)
I do the 70-80% stuff by feel, 3 sets of 5-8 or one set of AMRAP, or whatever works.
Your 3 week cycle takes 6 weeks, so you can probably deload a lot less frequently as well. I do it this way versus the lower/upper 'busy man' split because I do better with full body'ish workouts and don't handle lots of assistance very well - I do the above Triumvirate style (add rows to bench, pullups to press) and leave.