Comparing the draws. Here are the best players by round that Rafa, Roger, and Novak could face:
RAFA: Ferrer - Pospisil - Khachanov (or Muller) - Edmund - Anderson (or Thiem) - del Potro (or Stan) - Novak (or Roger)
NOVAK: Fucsovics - Sandgren - Gasquet - Carreno Busta - Roger - Zverev (or Cilic) - Rafa
ROGER: Nishioka - Paire - Kyrgios - Fognini (or Chung) - Novak - Zverev (or CIlic) - Rafa
Let's go round by round.
R1: Ferrer is old and declining, but who knows, maybe he'll be inspired to play Rafa. Nishioka had that one good tournamenta awhile back but really shouldn't challenge Roger. At all. Fucsovics is a bit trick and has improved greatly this year and probably presents the most difficult challenge.
R2: I think we've got a threeway tie. All can play at times but all are erratic and should be relatively easy to defeat.
R3: Khachanov is a good rising player but is 0-4 vs Rafa and has yet to win a set. No probem. If Muller gets in, that could be intriguing - but this isn't Wimbledon, so no worries for Rafa fans. Gasquet? Ha! Kyrgios is obviously a threat, but it depends on his health. But clearly Roger has the hardest opponent.
R4: Carreno Busta is sneakily good but Novak shouldn't have a problem. If this were clay I'd worry about Fog (or Chung), but not on hards. Edmund presents the most difficult opponent of the three, at least for Rafa, who took three sets to beat him at Monte Carlo. Could be interesting.
QF: Roger has the worst opponent, then Novak. Obviously they are far more concerning than Anderson for Rafa, who he beat quite easily last year.
SF: I'm going to call this a wash as del Potro, Wawrinka, Zverev and Cilic can all be similarly dangerous, depending upon the day. Delpo is a serious darkhorse to win this, but Zverev is due and we know what Cilic can do when in form. Stan is almost back but not entirely.
F: A wash.
All things tolled, it is much closer than some are saying and I don't see a huge conspiracy at work. The main difference is the quarterfinal, but that's just the luck of the draw and it was 50-50 and Rafa got lucky. But I think the other six rounds are close enough not to see a huge difference. Rafa does have the easiest draw because of the QF, and Roger probably has it slightly worse than Novak, but the gap isn't so large that an in-form Roger shouldn't be able to overcome it.