I think this is more likely the case. I think Sneed may well be the better CB. But they don't think he's enough of an upgrade to warrant what he signed for.
Were it up to me, I wouldn't have traded for either Sneed or Davis, I would have signed Kendall Fuller for what Miami did. That said, given the cost of only Sneed or Davis I'd have chosen Sneed. I don't think Davis will resign with us for substantially less than what Sneed just signed for. In any case, I'm fine with Davis as I have enough faith in Holmes and this regime to get it right in the end, even if they whiffed of CBs last offseason.