Genoese crossbowmen need their training time decreased, 22 seconds is simply too long compared to other unique units and makes them extremely unviable in any sort of games unless youre imperial with plenty of castles
I completely agree, in fact, a lot of us here do and is complaining about this for several months, and there were already several topics in the forum.
Here there is the most recent and comprehensive one:
Here there is also a discussion about how to improve the Italians on land, mainly by giving them free archer armors techs (no blacksmith required) or by giving +1 pierce armor to standard xbows and skirms, either one those bonuses combined with a reduced training time for the GC.
Another more recent idea is to give them a bonus that makes their all their foot archers (standard archers/xbows, skirms and GC) training 40% faster, so to solve their GC problem and helping them a bit on land.