NSA should be aware of the Atlas Recovery Vehicles, available from Forge World. Tanks are holy relics of the Mechanicus and not to be abandoned, willy-nilly, on battlefields.
Injured Guardsmen, on the other hand...
Well constructed and very nicely weathered, but the way war goes down in 40K, I'm surprised they bother recovering vehicles. Aren't IG troops and gear just shoveled down the war hole with no regard for common sense?