yep, it does not cause serious problems. If a names entry isn't listet in the languagenames.cfg, the game takes the name of the ship.cfg in data/sea/yourship, for example "Ftboot" for the Flottenbegleiter or "CLDido" for the Dido cruiser.
But it would be good anyway, if all names-entries could be listed for pasting them into your languagenames.cfg. Many players may use different mods and different ships and when copying an other names-file they will lose their shipnames.
lets start
For the Flottenbegleiter the standard entry is
Ftboot=Flottenbegleiter
Other names that make sense:
Ftboot=Fleet Escort
Ftboot=Geleitboot (From 1941 on the Flottenbegleiters were called this way), or
Ftboot=Escort Boat