It is a discrepancy. We can't always get what we want, and in this case we get a discrepancy.Trying to understand the difference between LORD and God, I've never heard of it before would you say "God" is the Trinity together?
I think it has to do with time and that perhaps that God is discovered not quite in the way that is described by tradition. From Archeology we know that the Canaanites are surrounded by enemies for thousands of years. They receive somehow or develop somehow a system of laws and a covenant which allows them to live together in peace -- many tribes of Canaanites. One theory: They somehow run into the divine when they begin speaking about their covenant as if it is a being. They begin to talk about something beyond their covenant which they have discovered through it and which today we call 'God'. They begin to speak of the one God, or so I imagine. The discrepancy however is not my imagination. 'God' in Christianity and 'LORD' in Jewish scripture often don't seem equivalent.
There is another possible discrepancy that explains the first: Archeology vs. Scripture about the genocide of the Canaanites. Archeology currently indicates that rather than being massacred by an invading Israelite tribe the Caananites all merge and become the Israelites. The scripture story about a massacre may seem to be a misdirection, however it is consistent with the usages for war that we find later in Christian scripture. Christian scripture does not consider physical war to have any value. It may be that the wars of Moses are actually about diplomatic conferences and alliances rather than stories of physical battles. I can't say that for certain, obviously. It simply seems to fit the situation to me and seems to make sense of everything. Complete disregard for the value of war and swords and chariots is very uniquely Jewish and is easy to demonstrate, so I think it not far fetched.
The term we see in our English bibles is 'LORD', but this is not the same as the term 'God' which we see in the Christian scriptures...not exactly. Perhaps Abraham just didn't know what he was dealing with. Perhaps he thought that he must be tested. I would certainly not kill my son for God, though I might for the good of a country or to seal an alliance which was being tested.