If I couldn't BF, I would use a wet nurse - and I don't have an issue with them BF directly - although I would like to feed the bub EBM myself sometimes. I think there are other ways to bond, plus my experience with DD is that she still loves my BB's but doesn't feed anymore, and I can see how happy she is just being able to snuggle into them, so I think the experience of a bub feeding from someone else may then lead to the bub getting the same pleasure and bond from just being close to my BB's even though not feeding with them. With my mum for example you can see how much DD likes to snuggle in, and I have seen her reach out to friends BB's for comfort and I believe there are benefits to the close contact from BF but I don't believe that BF'ing without anything else leads to the strongest bond so I wouldn't feel threatened by a wet nurse. In the animal kingdom bubs often feed from relatives but they still know who their mum is.