If I am reading your descriptions right, you have two very different strains of bees. Do not try to compare one to the other directly.
On the italian, expect larger brood patch, more bees production, overall bigger clusters, high food consumption, lots of feeding, lots of wondering and robbing, tendency to swarm if you are not keeping on top of space needs.
On the carni (sk hybrid) expect smaller cluster, smaller brood patch, higher honey production, frugal on stores (less feeding), and keeping to themselves. Much much smaller winter cluster.
To see empty 2 to 5 queen cup placehders in a carni hive is absolutely normal. Means nothing. Carry on with no concerns. Leave them in place so you know where they are. Check them at each inspection for egg or jelly. Doubtful that there will ever be anything in the cup until the queen is old or injured and obvious.
Hope that helps.