Perry Miniatures perhaps? I don't have a direct comparison with the Perry and Black Tree Italians, but I do have some of Black Tree's WWII figures and they seemed smaller than Warlord's range.
Otherwise Warlord's older Italian metals may work better than their newer plastics. And I get the impression that all of Wargames Atlantic WWII plastics have similar proportions to Warlord's plastics - based on their WWI German figures.