Where I see the two 'realisms' as working hand in hand, co-operatively rather than in opposition.
The first gives a player a setting that can most easily be related to and-or imagined - it looks and works just like Earth except hey, there's a Dragon flying over those trees, the sun is orange, and someone just made those trees grow 100' in a hurry. A DM who thinks it all through can even come up with a homebrew underlying model of game-world physics that accounts for and seamlessly blends magic with real-world physics, on which you're all set.
Once the first is established, the second - the consistency piece - just makes sure it keeps working the same way all the time.
Thus, when I speak of realism I'm including both types above.