Declaring Vehicle Shooting ; do i have this right?

[9x19 Parabellum]

So I want to add a couple medium tanks to the force I'm building, I think I've decided on the Sicaran Punisher because I really like the rotary cannon on it.

Now first I read that a vehicle has to declare all it's shots at the same target, which for the SP means infantry.  So I figured I'd want to dedicate it to that and put heavy bolters on the sponsons. 

Then I read that "Any vehicle mounted weapon of Str 6 or less is designated as a defensive weapon" and that defensive weapons can always choose to shoot at the "closest visible infantry unit in arc".

Since the Punisher Rotary cannon is Str 6, this means its defensive even though it's the "main" weapon of the tank?

Furthermore, do I understand this to mean that I could upgrade the sponsons with lascannons and add a pintel multmelta so I could declare those weapons against tanks/armor, etc, and always choose to shoot the Punisher rotary cannon at the closest infantry unit as it is Str 6 and thus a defensive weapon, even though it's the main weapon?

Do I have all that right?

[MichaelCarmine]

Close - the pintle mounted Multimelter also counts as a defensive weapon, as do all pintle mounted weapons.

So your "battle weapons" would be the Lascannon sponsons, which shoot at a vehicle, and your "defensive" punisher cannon can shoot at a different infantry target and also can shoot as part of a reaction, as can the pintle mounted MM.

EDIT: Also - if you choose a target for your sponson mounted battle weapons (Lascannons/Str.7 and higher), that only one of them can see (thanks to firing arcs), then the other Weapon (even if it is a battle weapon) can also choose a different target of any kind in its own firing arc.

Edited July 15, 2022 by MichaelCarmine

[9x19 Parabellum]

Thanks Michael, that's very helpful!