So... I was playing a bit with the map generation and found something to be really weird.
Turns out that lowering the frequency of ores makes the size larger.
At that point, the size property has little effect on the size.
I made some screenshots to show what I mean:
https://i.imgur.com/S77WeEi.png
https://i.imgur.com/fMnhJ1O.png
https://i.imgur.com/cgXEzku.png
Comparing the last 2 images, the size comparison should be 1:36 (17% -> 600%), but it appears to be more like 3:4.
Comparing the resource piles to the biter camps for example should give some impression of their massive scale.
Also, I compared with Angel's ore mod to see if it was something that happens for all mods, but those appear to work fine.
https://i.imgur.com/WJboi5w.png
The highlighted ones are crottinnium and saphirite ore, which have the same settings as everything else.
If required, I could also post one with a banana for scale, but I guess this explanation is good enough :D
Versions:
Factorio: 0.18.12
Factorio Standard Library: 1.4.1
Pyanodons Coal Processing: 1.6.2
Pyanodons Coal Processing Graphics: 1.0.2
Pyanodons Industry: 1.4.4
Pyanodons Raw Ores: 1.9.9
Pyanodons Raw Ores Graphics: 1.0.1