Views Relationship: Set delta for "Taxonomy term referenced from field"

OK, I'm struggling with this one. I've tackled the problem from a few different directions and can't seem to make it work.

Forgive me if the example I'm using feels a bit obscure. The real example is more complicated, I can elaborate if it's required.

Let me simplify:

I have a Taxonomy. Let's call it foo. Foo has multiple terms, and each term has a weight

I have a Content Type. Let's call it bar. Bar has a multiple field reference to foo, and can have 1 to unlimited values.

Let's say foo has 3 terms with entity IDs of 1, 2, and 3.

Let's say I have a bar content type called "bar_123", with a field_foo value of 1,2,3
I have three other bar nodes: "bar_1", "bar_2", and "bar_3", with single values of 1 , 2, and 3 respectively.

I have a view of taxonomy terms that lists all terms of type foo, which has a relationship to bar. The result would look something like:

EntityID 1
  bar_1
  bar_123
EntityID 2
  bar_2
  bar_123
EntityID 3
  bar_3
  bar_123

Now here's the catch. I want to use foo's weight to display the bar's in a certain order, but I don't want duplicates. In fact, I don't even want to display the entity ID. I want a result of:

bar_1
bar_123
bar_2
bar_3

There are several ways I've attempted to tackle this.

1) If I use aggregation, it works, until I sort on foo's weight. Then all the terms display again (since I'm now sorting on a term that isn't aggregated). I know this is a faulty use of aggregation, but I really don't want to aggregate - I really want to join on only first term in field_foo.
2) If I try to filter on field_foo's delta = 0, even more terms display... the relationship join to bar seems to have all possible delta values, regardless of which element delta field_foo was actually joined against.
3) DISTINCT appears to be failing entirely. (Even if I tell the query it can't rewrite the result)

My core question comes from #2: Why doesn't the joined content type (bar) correctly display its delta? My result looks something like:

EntityID: 1
  bar_1 0
  bar_123 0
  bar_123 1
  bar_123 2
EntityID: 2
  bar_2 0
  bar_123 0
  bar_123 1
  bar_123 2
EntityID: 3
  bar_3 0
  bar_123 0
  bar_123 1
  bar_123 2

Shouldn't it rather look like:

EntityID: 1
  bar_1 0
  bar_123 0
EntityID: 2
  bar_2 0
  bar_123 1
EntityID: 3
  bar_3 0
  bar_123 2