I think the success of an NFL offense is too complex to boil it down to these two things. An o-line can be top 5 but is way better at run blocking than pass blocking. The OC may not be a good play caller (i.e. knows how to get a QB in rhythm, or set up bigger plays, or situational play calls). The OC may also not be a good play designer (i.e. creating ways to get star players the ball in space, playing defensive matchup rules against them). These are only a couple of things that go into it that muck up the waters for this debate.
I think the success of an NFL offense is too complex to boil it down to these two things. An o-line can be top 5 but is way better at run blocking than pass blocking. The OC may not be a good play caller (i.e. knows how to get a QB in rhythm, or set up bigger plays, or situational play calls). The OC may also not be a good play designer (i.e. creating ways to get star players the ball in space, playing defensive matchup rules against them). These are only a couple of things that go into it that muck up the waters for this debate.