As I said, there are two different subnets active with the VMnet2 and VMnet3 in the same VM. If you had two network cards with different subnets on a physical machine with that setup you would encounter similar routing problems. So it has nothing to do with VMware.
You may not need ICS at all in this situation. Just have two virtual NICs connected to NAT in the same VM to be in the same subnet; so that the VM has internet access, the IOT device has internet access. I think I would stop here now.
