We used transports from classic, and introduced them as TRAINS.
They cost 6, moved 3, and could carry 3 inf, OR 1 art. They couldn’t be used to blitz, BUT they could be used to attack an enemy territory.
There was one catch… they didn’t take a hit, and they could be captured… and they also couldn’t retreat from battle.
They could be strategically bombed and destroyed aswell.
It made for a great additional unit, especially if you’re into infrastructure/transport kind of stuff.