It's mostly about you, not the circumstance.
We've done it both ways, and it has worked out positively both ways. It has work out well because my wife and I are relatively dog savvy people. However it can also be a disaster either way, but that too will be more about the dog savvy of the owner, and less about the people/child savvy of the dog.
Either way, just be honest with yourself about your own capacities, then the advisable decision will be fairly obvious.