Upgrading a different skill character, effect other weapons?

Does it affects my missile damage if I upgrade Mortimer's area damage?
I'm upgrading Blastian alot, because he's an expert in missile damage, but what about Mortimers damage, when we talk area damage, but for missiles? Or does it only count for mortars?

 

I'm pretty sure it work for Missile or even cannons. While you aiming cannons its have green drop point sure effect by Area Damage but too small to notice.
If only work for mortars it would specified ( Mortars only)

 

I'm under the impression that all point damage refers to cannons, carronades and anything without aoe. While area damage applies to everything from torpedoes to mortars and probably missles too since they have splash damage, although mortimer gets one skill that basically gives a minor critical if you can land the mortar on someone directly.