The matching score is probably the same, or very close in both ways, but this fact does not necessarily help in a three-way scenario:
A <-> B: 80%
A <-> C: 90%
B <-> C: 70%
When you search for A the best match will be C, but if you start with B it will be A. If one of the accounts has a smaller sample set as in GP's case, the gap could be quite big. I'm still in disbelief. I think one should run the operation in reverse after obtaining result set.