The European situation is silly.
AF allows a cabin luggage 55x35x25 and an accessory (smaller second bag). Total weight for the two 12k (18k for J)
LH allows one a cabin luggage 55x40x23 plus an accessory in Y, and TWO cabin luggage plus an accessory in J. Each cabin luggage limit is 8k.
BA allows one a cabin luggage 56x45x25 plus an accessory. Each item can weight up to 23k (46 over all). No additional benefit according to class or status.
BA is the most generous in Y even for the size of the accessory.. But the differences are ridiculous.