I would have thought that the finer grain would be a reason to use Rodinal with it, as Rodinal doesn't soften grain.
In my experience, Rodinal makes the grain considerably larger and more visible compared to D76/Xtol, DDX or just about any standard type developer and while reduced agitation controls grain, the result is still larger grain by a fair margin.
Rodinal may not soften grain, but it sure doesn't hide it either. To be fair, I do not think D76 1+1 or Xtol 1+2 (or 1+3) softens grain either. Try D100 in Xtol 1+2 and blow it up huge. When you eventually see the grain it is sharp as hell, just waaaaaaysmaler than it is with Rodinal. Same goes for TriX, Neopan, Foma 100 etc.
I would not personally use fine grain and Rodinal in the same sentence, unless talking an ultra slow film and even then, in relative terms, almost any other developer would produce finer grain, but considering what you can see on print, the Rodinal may still be to all intents and purposes 'grain free'.
Roger is spot on regarding my experiences. Most of my Rodinal film speeds are half box speed, whereas dilute Xtol and DDX are box speed minus 1/3 stop in most cases so abot 2/3 stop difference. Dilute D76 (1+1) would be somewhere in the middle.
I use quite a bit of rodinal, alongside dilute Xtol and frequently mixed, because it can add more bite, more visible grain and a straighter lie in the highlights, when I want that look. I don't have a single combo in which Rodinal produces finer or less visible grain than any of my other devs.
