All this makes him the most experienced ESA astronaut, both in terms of total time in space and of total EVA time. He's also one of the very few Europeans to ever be ISS commander. If you need to pick an ESA astronaut to go to the moon he's not only the best pick, he's actually already at the top of the list. The original plan was to take an ESA astronaut on a later Artemis mission. What Macron is actually lobbying for is that this happens on the first crewed landing instead. Thomas is the most qualified astronaut (both current and ever) outside of the USA and Russia, and if my data is correct, the 8th most experienced currently active astronaut worldwide, and of the 7 in front of him, only 1 is not Russian. I'd say that makes him objectively very fit for the job, not just from ESA but from the whole pool of western astronauts.