The 5 veterancy levels are now arguably better then the 3 vet, as they've been nerfed, but they are nothing to really gain an advantage in during combat. So no. I don't understand salvaging, it's border line useless/barely used, as the economy is actually somewhat decent now.
i would disagree with you about the vet not helping with combat
all okw "combat" infantry get to heal out of combat, that means you can skirmish, take some hits (RNG allowing not drop a model) and only soft retreat and heal up, ready to jump on the next skirmish in the enemy territory- or at the VERY least, your units heal up while retreating letting you simply reinforce and move out, no need to wait until them medics fellate each and EVERY model (i feel this is why shrek blobs are allowed to be so potent, as down time is minimal)
ive also FREQUENTLY used sturms stun nade to secure wipes on retreating groups ( a well timed stun nade halts the retreat and requires another one to get to safety) and their medical supplies are miles ahead of first aid and let you keep up the pressure
at vet 3 the rakk gets guaranteed pen and bonus damage out of camo
flaktrak gets muni free smoke at vet 1
ober smoke is the bane of shock troops and rangers
HELL a couple vehicles can even disappear and run away!
okw have beyond powerful vet and greatly out match that of the ther factions with no drawbacks
AND
use salvage
seriously
EVERY wreck or weapon you dont want
its FREE fuel
meaning the okw economy isnt simply on par with everyone else's... its SUPERIOR
by the time my tiers are built sometimes ive salvaged nearly 50 fuel or more in some games ( effectively making that vet 4 luch that ran over a mine after 50 infantry kills cost 15 fuel), all at the low low cost of also getting 5 levels of vet and sexy bonuses when i tech up