I think this would be a great important and necessary change for the devs to implement an option to state veterancy accurately and precisely (in numbers %). Its current description is vague and seems according to some units outdated. This is problematic. This can not be ignored. It should be dealt with.
This would be greatly appreciated!
I would say Relic doesn't plan to add this. Maybe in CoH3, this will be a thing but for now, you will have to use the Numeral Veterancy Descriptions mod to get accurate veterancy stat bonuses.