I think they should have grenades, 2 light weapon slots is a recipe for an effective AV suit (1 anti-infantry for self defense 1 for AV weapon), yet no grenades means no AV grenades; kind of ruins it.

You want a rifle, a dedicated AV weapon and AV nades?! Boy, all reward no risk.

You seem to be ignoring a lot of downsides. Relatively low speed, poor shield recharge, low slot count, poor scan precision, big scan profile. I would not be apposed to to trading something else for the gain of a grenade slot.

In most games with both vehicles and infantry, infantry does not have to sacrifice anti-infantry weapons for AV capability, but in Dust you usually have to because a swarm launcher takes up a light weapon slot; this makes AV even harder because not only are the tanks in Dust extremely (over)powerful, but you are also very vulnerable against regular infantry, so you might get killed before even finding the tank you're after. The commando's dual light weapon slots allows one to be both competent against infantry and vehicles, but the lack of grenades makes it have a huge drawback in dealing with vehicles; this keeps it from being an ideal AV suit.