it's also not just those two ranges. more examples:
Golem Earthquake vs. Tauros: 119-141 (33.7 - 39.9%)
Rhydon Earthquake vs. Tauros: 133-157 (37.6 - 44.4%)
for a common example line where this matters,
2 Tauros Body Slams is 53.8 - 63.4%
so if you do the classic bull war Slam Slam and now you're in a hyperbeam mindgame, and you catch the hyperbeam with your Rock:
Golem's odds to kill the Tauros with EQ are abysmal (total roll 87.5-103.3), Rhydon's are nearly 50% (91.4-107.8)
Golem Rock Slide vs. Exeggutor: 97-114 (24.6 - 29%)
Rhydon Rock Slide vs. Exeggutor: 108-127 (27.4 - 32.3%)
chipping golem down takes a while longer - you're also gonna be mixing in bodyslams and earthquakes realistically over several entries, but golem very realistically will need 1 more entry to break it a lot of the time. of course there are infinitely many ways this can play out and it's virtually impossible to come up with a concise example of this damage difference mattering, but just because you can't calculate those scenarios a priori doesn't mean that they won't happen in game.
also the way the numbers line up against Snorlax is comical:
Golem Earthquake vs. Snorlax: 150-177 (28.6 - 33.8%) -- 0.5% chance to 3HKO
Rhydon Earthquake vs. Snorlax: 169-199 (32.3 - 38%) -- 97.1% chance to 3HKO
The point is not missing any one specific roll, the point is all of these rolls combined, and infinitely many more practical game situations where you will need that extra 5% for one reason or another. It's not going to be a single calc to demonstrate the difference, but rather it's the incalculable number of scenarios that you're not going to be able to draw up while theorymonning, but will very practically happen to you in games. Rhydon is just meaningfully much more efficient at trading in these ways; Golem wants to explode because it's really not good at doing Rhydon's job of EQing things over and over. It CAN try, when the situation is good enough for it, but otherwise just wants to peace out and 1 for 1.
Stats matter a lot, it's not just moves and types. And there's no clear and easy way to explain why and how much each stat matters on each Pokemon, cuz the reason is like 30 different calcs each time. So it's moreso a feel you build from playing and running into all of these scenarios and noticing "wow, I only barely hit that roll, lesser stats would've killed me there". or "wow, I was 1% off, if this mon was stronger I'd have hit it". Over and over and over until you really fine tune yourself to be perceptive to all this stuff.
With Rhydon/Golem specifically, because one of the desired duties is precisely getting to click like 8+ of your EQ PP over a long stretch of turns, punching and punching and punching, the stat differences are amplified. A Rhydon that only clicks 1 EQ before dying probably wishes it were a Golem who clicked Explosion instead. But most Rhydons have ambitions for much more than that, and when that works out as desired, Rhydon is miles better and it's not close
