Well, not really. There's some science involved, and not poop science.
The main sewer line is sloped properly (.25"/foot), at the 75' plus 2' from the toilet into the crawl space, we have 77' of length and about a 43" drop from distant toilet to end of line. For the second floor toilet, we have a 13' drop plus another 12' run, 25' in length. That run is a 3" drop, plus the vertical pipe of 156" for a total drop of 159".
Using a pipe flow calculator, whether you have a gallon of water or waste from either toilet, in the distant toilet the velocity of the water/waste would be just under 7'/second. From the second floor toilet, it would be just over 24'/second. So, quite a difference. Water will have less resistance to flow than solid waste, so that extra flush of water will help push things along from the first floor toilet that's so far away from the sewer exit from the house. The second floor toilet(s) will have quite the velocity going and a much shorter distance to get to the exit; everything will be moving fast and exit quickly.
I don't make this stuff up. There are pipe flow calculators to do it for you.
No clogs yet anywhere, so I guess they did it all correctly...
Only once did I ever have to have a pipe snaked. Half my fault, half the "plumber" (actually a remodel contractor). My bad for using the disposal to chew up a bunch of asparagus ends (won't make that mistake ever again!). But the real plumber who came out noticed the drain in the basement for that sink; the contractor put two sharp 90 degree ells very close to one another. Shouldn't have done that. We eventually changed that, and learned our lesson on what to put in the disposal. Very little!