Interesting, I wasn't aware of that. What about priests do they fall under the same problem? If so then my suggestion is to make price balance their effectiveness.With the Inferno Pistol upgrade the Veteran Superior's damage becomes very potent. With the Imagifer and the Veteran Superior together it would make the squad have high damage and high survivability which could be too much. I'll have to see.
So would it work this way? Say you use normal SOB unit with flamer model but with heavy flamer stats? Same with seraphim's instead replacing normal unit with sister superior model that has inferno gun? Not the ideal solution, but something to think about.Even if the weapon upgrades exist for other units, the only way to add weapon effects to a unit which doesn't have them is to change the model.