DS2 Vehicle design question.

When designing an APC, are the mounted infantry units considered a
"weapon" for the purpose of weapons fit?

Andy Cowell's page won't let me put 2 line infantry and a weapon in an
APC.

I can put in 1 PA element (twice the space!) and a weapon.
Theoretically, then, 2 elements of line fit in the APC.

The DS2 rule book on p.11 specifies weapons fit, but does not say
specifically that infantry are a "weapon".  The chart on p. 16 lists
infantry as a weapon/system. Is this a semantics problem, or what?

In any event, I think mounted infantry would be a pretty poor "weapon",
all things considered.

What is the official deal? 

Thanks for your help. . .

Paul, whose APCs must be class 2, because they're smaller than his class
3 vehicles.