Any large wild clowns are prone to being poor shippers, I recently aquired a pair of akniydos and although no disease issues and great eaters they are shy, very and dont tolerate any movement around the tank which is a 60 cube, I think yours will need a big system to be happy as they range along way from their anemones in the wild.
The wild caught melanistic clarks we get here are in thailand are terrible disease magnets, they are found in mertens anemones and you see the swimming 5 to 10 meters from the anemone on dives in the andaman. You see lots in the lfs but nearly all die quickly. I dont think yours are from vanuatu what with the third bar present, a better guess would be coral sea between new guinea and the northern tip of australia.
If they were labelled aussie then this makes more sense to me. The look good and strong, how do they eat?
I mix fresh chopped prawn, scallops and their roe, oysters, cyclopese, formula one pellets (crushed) and chopped nori (algae very important in clownfish diets) chop it real fine and freeze in a ziplock, they will go crazy for it.
good luck