How would I go about picking which one of these edits is the best, given a lack of street view?
Is this the sort of thing in which I just mark as “unable to find proper location,” or should I just pick one based on arbitrary street view accuracy and call it a day? Concerned with it affecting my score, as I assume there will be no clear consensus (I guess as a side note, would something like this affect my score?)
To my mind they’re all correct, so i just pick one and move on
No idea what that means for agreements etc
In that case I would pick “unable to find a proper location” as they are all together, sometimes is impossible to choose one against the others. Just in case, this is my personal opinion and not something that everybody must do just because an Ambassador said it, we always need to use our best judgement 
I also chose “unable to find” when one is not clearly better.
I think this tends to happen when people thought their edit had glitched and needed to be submitted again when it never got a decision. Or forgot that they had submitted it. (Confession time: I have done both.) We only just got the ability to see edits on our contributions page so there was no tracking them.
My hope is that marking it “Unable to choose” will still bring the edit to a resolution.
I also choose “unable to find”. And my rating stays at “Great”.
It wouldn’t make sense to say “I don’t know” is wrong. I know if I know or not - they can’t say I do know what I say I don’t know.
To expand one of cyndiepooh’s speculations - I think it’s sometimes because of the backlog. I still have around 15 (text) edits In Voting from 15 months ago. Others could have come along and made basically the same edit in the meanwhile. For that matter, I could have gone back 6 and 12 months later, forgotten that I had the edit already in flight, and submitted it again.
