Hello everyone! I'm very happy to say that unit veterancy is now in the game! The bonuses from your units gaining vet in the battle starts out relatively small, and is not too difficult to gain, but vet 2 and 3 gain even better and better bonuses.
The command squad has its own form of veterancy - it gains shared vet from nearby units just as the British do, but vet 3 is particularly important. Once your command squad has gained vet 3, a special one-use doctrine specific ability is unlocked. These powerful abilities buff your infantry across the entire map, and so should be saved for the right moment. Needless to say, the amount of experience to unlock these abilities on your command squad is quite steep, and you will need to keep them near the action to get as much of the combat experience from your other units as possible.
Here is a game showcasing the latest veterancy additions:
UPDATE: There will be a patch coming out shortly. Here's some more in game footage, for your enjoyment!
