if only they had a rule like "excess from 23 to 32 kg counts as an extra luggage", so that in C, you can bring a luggage of 30 kg and one of 20 for example.

Before, luggage limits were all 23/32 kg in Y/C i think, to make it 50/70 Lbs... and then it changed, to make "more clear", 20/30 kg. I am sure that soon they will change the limit to "rounded kg" at least for flights from Europe, 20 kg per bag.