Well .. they gave us the aquaduct and sanitation oh and then there's the roads, education .....Yeah, what have the Romans ever done for us??
Wholly agree that a young plumber won't know nor be expected to know how wipe or manipulate lead pipe the traditional and trusted way but also TBF, there are a whole handful of universal fittings and adapters to convert lead pipe to a more modern equivalent, so TBH I would certainly hope that they would been trained and know how to clean up/round out the pipe and then use a saw properly and use the fittings properly