OK, looks like you have multiple scenarios available. The multi-subnet one contradicts with what VMware supports and recommends for port binding however it should be there for a reason and that is probably the array architecture.
Can you get someone from Dell side (i.e. engineer from a partner company that sold you the MD3200 box) who could explain the consequences of both scenarios - multiple vs one subnet?
If you're on your own and the array is not in production yet, then test them both and do a benchmark for performance, try unplugging the cables / powering off switches to test failovers. That should give you enough information to base your decision on.
WBR
Imants