AppleShare PC 2.0 is compatible with DOS 4.0, but it appears that you missed
one item.
You need to select "3" as the primary interrupt line for the MLID used by this
card (ETHER$). If you leave the default interrupt line intact, it will
certainly fail.
Both the default primary memory address 0C0000H and the default primary port
address 0300H are correct and do not need to be changed.