a chinese fleet going to ITaly would certainly have to take thte long way around. there was no direct sea route to china back then - they’d have to go around the horn, at the very least. than find the relatively narrow gap at gibraltar and enter the mediterranean and finally come up against italy - whilst missing every other landfall.They'd have had to make stops along the way to find provisions. As you indicate, why Italy and why Venice? Spain and/or north Africa should have warranted visits.