Just because the evidence provided supports a position, that doesn't mean it makes that position stronger, if another position is equally supported.
The other position is not equally supported- it requires extra evidence which is not available. The conclusion presented by LFJ does not require extra evidence.
I disagree that the concept of empty hands gaining weapons adds any complexity
It is a more complex explanation for the facts available, requiring an additional empty hand system of which there is no longer any trace in the system or elsewhere.