Instead of obtaining the model for instant use, it would be cool if battlefield salvage could potentially accelerate the discovery of military techs, or if the tech has been discovered, provide a small bonus to research.
Either that (or additionally) help discover a model, or provide a bonus to model research if the model has already been discovered. Or even better still, finding/salvaging a model/design from an enemy may prompt a discovery of a potential counter model/tech.
After all, many military technologies were developed in response to what the enemy was using, and what they were doing with it.
Alternatively (or additionally), simply enemy formations could potentially accelerate discovering formations or assist in operationalising them, or assist in discovering postures.
Not sure how feasible it is to do this with the way the game works currently, as a system such as this could quite easily become ridiculously complicated and convoluted in no time. But in theory, some obvious/basic counters (e.g. potential anti-armour tech when you discover enemy armour) should be viable - even if it's just a hidden thing that happens in the background (e.g. increase the likelihood of certain tech/models being discovered based on what you've scavenged from the enemy).