No exat numbers, just a thought.

One part of the balance - is to increase both med bots hitsize and med guns dispersion - that way meds keep the same effectiveness against each other but dractically reduce their chances to hit something small.

Then another way - there are few approaches. Either raise med bots resists against light weapons - to make small weaponry barely scratch, or even make med bots immune to all the incoming damage below a certain level - like, light guns can hit you only if crit hit, otherwise 0 damage.

That covers just a damage so far. Next will come later.