Jordan, Muscovy ducks are as tough as they come. Our khakis and Ruens are pretty tough too. The Indian runners are not necessarily weak but they can't fly so they are a bit helpless. From my
experience any duck is tougher than the toughest chicken for what that's worth. Also, for some reason, predatory birds seem to not see full grown ducks as food...we have had many chickens killed by hawks but not one duck! Now, no duck with its wings clipped is going to be able to handle a cat or dog predator. If you have the room, I would recommend getting adult Muscovys and clipping one wing (please make sure you google how to do this properly) at first and give them protection while they imprint on your location. After they realize that your place is a pretty nice place to be they should not leave. Our ducks fly out of their gated pond in the morning to forage and fly back in at night. If they see danger they either fly away or get in the pond.