I admire the Franciscan way of thinking about the incarnation. From the beginning God planned to communicate his divine life to humanity, to enter into fellowship with us, and with all his creatures. Thus, the World of God would have become man even without the original sin. In a way, let's say, incarnation is the whole point of creation.
The Franciscan way is very appealing because it shows that God wants to be close to his creation.
And what a better way to bring humanity into divine life than God assuming human nature?
This is the first assumption, and it seems true to me. The second assumption, however, is that the original sin could have not happened. I have my doubts about that.
This is Metropolitan Anthony of Sourorzh quoting Archiprest Avvakum when he talks about the harmony of the Trinity:
God says to his Son, 'My Son, let us create Man!. And the Son replies, 'Yes, Father!' Then, revealing the future mystery, the Father says, 'Yes, but Man will sin and fall away from his calling, and his glory, and You will have to redeem him on the Cross.' And the Son says, 'So be it'. (-- Encounter p70--)
So maybe this is true. Being human, entails the possibility of sin. Thus, from the beginning it was foreseen by the Father that the man will fall. In a way, it might have been too much to expect that the full human race, being made of imperfect rational beings, depending on the senses, would not ever have turned away from God.
At the end, the discussion between Franciscans and Dominicans may have been about an hypothetical that could not have been realised.
Could we conclude then the following? In the creation both the incarnation and the cross are included. All because God wants to be all in us.