The Lockheed Martin Havoc. What do they mean by "modularity"?

I'm gearing up for the interview with the folks over at Lockheed Martin and in doing my research I keep coming back to one unanswered question.

What is modularity when it comes to the Havoc?

From my reading S. Africa will have the most versions of the vehicle.  A Tank Destroyer, Command, Mortar Carrier, Fire Support and Infantry Carrier.

Unfortunately that still doesn't answer the question because Patria has shown that the vehicle can mount several different type turrets...so all those functions can be carried out by simply swapping out the basic setup.  I looked hard but was unable to find the Command version.  I think that will be most telling in how that vehicle is equipped and set up..is it a module swap or is it a distinct version.

Another major issue in the interview will be weight.  The Polish version of the HAVOC, the Wolverine is the heaviest version so far fielded.  The Marine Corps version will be just as heavy yet will be required to swim.  Indications are that the Poles gave up the swim requirement because of the weight gained with making the Wolverine anti-IED capable.  Seeing how Lockheed Martin and Patria achieved the same type protection yet maintained the swim requirement is something I can't wait to ask.

The thing is happening Thursday so if you have any questions to hit them with send them my way.