New to Satisfactory and want to be the very best. Help me with coal power please

Hello, I am new to getting into Satisfactory, but once I realized how endlessly complicated every component of the game was, i was hooked! So of course my factories need power, and I found it delightful that the wiki had such a good guide on coal power groups. The problem i found was that my build is not getting enough water and i want to know why.

I followed the 8:3 rule, with a layout just like the first one [here](https://static.wikia.nocookie.net/satisfactory_gamepedia_en/images/1/1b/Coal_Generator_Schematic.png/revision/latest?cb=20210729150625). i have put 8 coal plants right at water level (foundation squares literally on the water) and 3 pumping stations right nearby, with a bus of pipes across all 8 plants and fed by the 3 pumps, one at either end and one in the middle. But one of the plants still runs low on water. I could fix it by overclocking the nearest pumping unit by 15% and it then works fine. But like any good factory owner, i want to know why my setup doesnt follow the "2.66 extractors required" math and instead needs 3.15. What can i do to figure out whats wrong?