Just kidding. I've never tested Tmax 400 in Rodinal before, although for tonal scale of 1.05, that would be a little short. Should be around 1.25 range.
Film speed determines where you'll make the mark for Zone I, but that doesn't really play a role in density range. .10 is what you would get for Zone I, and 1.25 to 1.35 is what you would get for Zone VIII. So your range would be 1.15 - 1.25. At 1.05, you've fell short somewhere along the line.
Exactly thè problem with zone system testing, you aim for a target range of densities and you end up with numbers that when you are trying to print them they require magic in the darkroom.
Most enlarging papers can accomodate a negative with a DR of .8, add to that .1 for flare and .1 for printing with a diffusion source and you get a negative that will print properly in a grade #2 paper when it has a DR of 1.00
At 1.15 to 1.25 I would say you have overshot the mark.