It doesn't matter what the electricity is used for.
The system capacity is system capacity.
When we have high heat power surges, our local PGE shuts off some neighborhoods to have power for other.
It is not direct comparison, but maybe water flow is easier to understand.
You have 3/4" water pipe that supplies 5 sites with 3/4" garden hose each.
The idea is that those 5 RV will never draw water at the same time.
But if 2 will take shower at the same time- the pressure is going to drop. If 3 it might come to drizzle.
Now you come with booster pump and start sucking the water into your RV.
Do you expect the neighbors still having good water supply?