Tarzan is "only" riding 100 miles every 7th day which will bring his average down over the week.
It will be interesting to see how effective this tactic is - quite a different approach to Steve - I certainly wouldn't fancy a 100 mile recovery day, especially not "to allow me to race the next day" (presumably refering to the long races he plans to take part in during the year, presuming they commonly start on Saturdays?).
Tarzan's approach of faster for fewer hours in the saddle will require more energy than Steve's (in terms of work done in moving a bicycle over the same distance). How efficeint their respective physiologies are in converting this energy from food is another matter (and the current large temperature difference between UK and Florida will not be insignificant). Some simple calculations, taking into account terrain and wind, comparing their respective first days, tarzan needed about an extra 1/3 unit of energy per km to move him + bike.
Tarzan's plan on his website called for an average of 167 miles per day during January, and this was for a total about 4000 miles less that Steve's initial plan. I'm guessing he might now be registering a bit more than that given how well Steve has started! The next few days will be enlightening...