How is a training camp from 30th June to 13th July, including a friendly against the 2nd best team in Germany "almost useless" as preparation? Jet lag is not an issue that will impact the team a month later when the season starts and they will have two weeks of training, at likely a very good facility and hotel. If this was arranged for close to the start of the league campaign I'd be worried about the impact of such a long journey for them... but it isn't.