Assistance please - tier points

All
I am trying to maximise the tier points I earn when going to Las Vegas next year.... My question is, is the miles quoted on the Virgin Atlantic booking page correct? The Delta connecting flights are now showing as options (though generally more expensive than a direct flight) but if I book in this way, will I only earn the tier points stated (i.e. direct return flight showing as 5 tier points earned in economy - flight with stopover at SFO or JFK showing as the same)?
If I want to earn more, do I need to do them as separate tickets on the Delta website? (i.e. book LHR - SFO, then SFO to LAS, or LHR to JFK then JFK to LAS). If this is the case I am less keen to do it because of the baggage charges I may incur, so I suspect this is the case.
Sorry if this is a dumb question, but I have very little chance of maintaining gold next year so trying to think of some ways I may be able to do it.
Appreciate anyones help.
I am trying to maximise the tier points I earn when going to Las Vegas next year.... My question is, is the miles quoted on the Virgin Atlantic booking page correct? The Delta connecting flights are now showing as options (though generally more expensive than a direct flight) but if I book in this way, will I only earn the tier points stated (i.e. direct return flight showing as 5 tier points earned in economy - flight with stopover at SFO or JFK showing as the same)?
If I want to earn more, do I need to do them as separate tickets on the Delta website? (i.e. book LHR - SFO, then SFO to LAS, or LHR to JFK then JFK to LAS). If this is the case I am less keen to do it because of the baggage charges I may incur, so I suspect this is the case.
Sorry if this is a dumb question, but I have very little chance of maintaining gold next year so trying to think of some ways I may be able to do it.
Appreciate anyones help.