It sounds to me as if the gulls may be more likely to be the culprits. Hogs do sometimes tip bowls over – even water bowls, if they are fairly small. To them they are just like stones/small rocks to look underneath to see if there is any food there. But they will also walk right through water bowls and potentially stand on the rim and tip them over that way. But unless they are fairly fragile, I wouldn’t expect them to break like that. Gulls may drop bowls from a greater height – assuming they are strong enough to carry them?
You might be better off putting out larger plant saucers i.e. 8 inches or more (the bigger the better and the birds may use them as a bird bath, too) – that way the hogs are less likely to tip them over if they are full of water – not sure about the gulls, though!