Seabreeze. ..None of your comment explains the wide diversity of views very early in Xtian history. It seems clear to me that the story took hold in the imagination before theologians formulated it through metaphor.
The NT (and later theology) use a number of images in their interpretive schemes; taken literally they are, often, mutually exclusive. For instance, a ransom (paid to the master of a slave or captive to obtain his freedom, or, rather, make him a slave of or a captive to the redeemer) has nothing to do with a sacrifice (offered to a deity, either to make it favorable, as in propitiation, or to erase a certain "sin," as in expiation). The conflation of those two images (one from a commercial setting, the other from a sacral setting) in the WT catchphrase "ransom sacrifice" is literally nonsensical: if taken allegorically a ransom would have to be paid to the devil, or to personified "sin," whereas a sacrifice would be offered to "God". There is no problem in using mutually exclusive images as long as they are taken metaphorically: we simply have an indefinite number of metaphors pointing from different angles to "something" which remains essentially undefined. In one word: a mystery.