As an MMO, part of the joy is building, progressing and customizing your favorite squads as you take them along on the journey with you. You become attached and even a bit sentimental about certain Squads. I think there is a good opportunity to have their journey and achievements chronicled. I know I take great pleasure and pride in these little features (Such as dressing them up and equipping them).
I thought that perhaps since statistics recorded per campaign will soon become redundant, It might be nice to shift these stat recordings to a more intimate career record of your squads on a squad by squad basis.
Squads and even individuals are already given the credit reward in the final score screen. Lets keep record of the tally.
Please forgive the crude representations, these are just to present the “general” idea. I slapped together a few alternatives (with images from google). Someone better suited could truly make it a monument to the squads career.

Accolades
To further it, You could use the collection of accolades, badges, medals (like Hero of the Soviet Union, or Knights Cross, Silver Star) to earn customizations, or unique customizations, Much like Warthunder allows you to earn camouflages and ACE crews simply by playing them ALOT.
Imagine earning unique camo patterns, uniforms, medals and badges that you can show off on your troopers
Veteran Squad
It could Also be a way to Earn The Veteran Upgrade that has Long been present but unused. Unlocked by the squad truly being a Veteran squad. (Same as unlocked ACE crew in Warthunder)
This has the great benefit of providing infinite progression/re-playability beyond leveling up the squad, and fostering player attachment.
Just thought Id throw it out there.