Tech Progression without the XP (Not what you think)

Either way you cut it, there is no good answer to how to make the Tech Tree "logical".

Making the player into a super soldier?

• Kind of ridiculous because you enter the realm of making this into an RPG where stats and gear becomes the player focus.

Relevant XP sounds awesome, and I'd get behind it, but...

• It will turn into the achievement system where we're going to have to shoot the AR 100,000 times to unlock the Pulse Rifle, make 100 headshots to unlock the Sniper...

Tech Progression without the XP (Not what you think)