Nerf Italians on water and strengthen them on land. My suggestion:
Italian universities and university technologies cost -50%
Hear me out: Out of twenty of the oldest universities in the world, half of them are Italian. Before the end of the 1300s, Italy founded ten of the oldest universities, before most countries had any. The University of Bologna was founded in 1088! Rome has Europe’s largest university today as well. The middle ages were a true university boom for the Italians. The word university itself has Italian roots.
Sure, this would have them get ballistics slightly earlier on water, but also on land maps for their xbow. If they were nerfed slightly on water, this would be a nice hybrid bonus to compensate for that.