OK let me clarify a bit.
First of all, as can be seen from the referenced datasheet, RdsON is 500 uOhm not 500 Ohm
How do things like that work.
For example, I will use 4 capacitors 3V, 3000F, 3Wh, 260 uOhm, in series (12V, 750F) as a source.
As a conductor between the source and the transistors, let's assume a copper strip 20x5x500 mm with a resistance of 10 uOhm.
Regulation of the power supplied to the welded point is possible by the voltage on the capacitor, but mainly by the length of the welding pulse.
The length of the pulse, let's say that the setup is from hundreds of us to hundreds of ms.
I measured the peak discharge current of one capacitor and I measured just over 2500A