For mild steel and normal cut consumables (not fine-cut), this is the chart in the book.
As far as entering information for “tools” in Fusion 360 (not familiar with SheetCAM) the only information that flows from the tool profile to the g-code is the cut speed and kerf width. Amps is set at the plasma machine, the plasma machine determines the air pressure. The thickness of the metal is never really entered.
Some people enter the voltage and air pressure just for reference and sometimes people set the voltage in FireControl if you are not using THC/smart voltage.
Other issues like the pierce delay, cut height and pierce height are entered just before Fusion 360 converts your contours to the gcode, during post processing.
This is all of the tool data that is not currently being used by Fusion 360:
So, in a short answer, everyone (most) have entered some detail for each type and thickness of metal in their tool set profiles. How much information you put is up to you but basically, Fusion 360 is only using the cut speed and kerf width from the tool and then your post processor information is entered just before the g-code is assembled.
Here are some other reference charts:
