Index/Match/Large Duplication of items; not returning true values

Hi All,

I have looked through some of the pages on the forum here for a solution to this and although there are some close matches, none seem to deal exactly with this. If I have missed a post somewhere, please feel free to point me in that direction.

I have what appears to be a relatively simple problem. I have 2 columns, one with product names and a second with product quantity. I am running a Large function to extract the top 10 products based on quantity. I then run an Index/Match function to extract the product name. I am running into an issue where there are identical values for Quantity and the Index/Match function is only returning the first value it finds for producst. My query is 2 fold:

Firstly, my understanding of Index/Match is that you are creating a reference, ie, this is the 12th value in this column and you are then getting the 12th value from your index array. Based on this assumption the Index/Match formula should work regardless of duplicates because you are in theory returning a matrix reference point. So my first question is how is my theory falling down here?

Secondly, should I be adding an IF statement into this Index/Match function to some how deal with duplicates? Am I using the incorrect formula?

Please see the attached spreadsheet for an example of what I am referring to.

Thanks
Darren