Five years is a good time, but it could be done even faster. If an apprentice comes with a mind of an engineer brain in such tailor shop and he is excellent with his fingers, accurate with pedantic mind. Cutting is mechanical work, drafting and calculating with adjustments and eye measuring plus using all kinds of forms, (Schablonen). Cutting is easier than making a suit. It all depends if someone teaches you straight forward, without keeping any secrets. The problem is that such a good apprentice rather becomes an engineer or doctor instead a tailor or cutter for a lousy wage in general.
It only takes someone 30 years to become a tailor/cutter, when he must figure out everything by himself and is on its own. Tailors have the tendency to over think stuff very easy and after they did something a couple of years wrong, they figured out that some other tailor could have taught him this in 1 minute.