Okay, you only need 6 documents with each name on, approximately 4 months apart and only from the last 2 years.
So, from the list you've given above, you have:
Nov 2015
1. You: 19th Nov 2015 A ground rent bill sent to myself
1. Your wife: ?
March 2016
2. You: ?
2. Your wife: P60 April 2016 (though not ideal as it should be something from March)
July 2016
3. Joint: 6th July 2016 Mortgage correspondence to myself and my wife
Nov 2016
4. Joint: 5th October 2016 Water bill correspondence to myself and my wife (ideally you want something from November, not early October)
March 2017
5. Joint: 5th April 2017 Water bill to myself and my wife
July 2017
6. You: ?
6. Your wife: ?
(Nov 2017 - extra one)
7. Council tax bill for 2015/2016 - issued 26th October 2017 (again, ideally should be from November)
So, you are currently missing documents from the following months:
You:
March 2016
July 2017
Your wife:
Nov 2015
July 2017
Also, if you are using separate documents for one month, they should be dated as close together as possible.
For example if your November 2015 document was issued on the 19th, you'll need a document for your wife dated as close to Nov 19th as possible. And if your wife's 2016 P60 was issued on April 5th 2016, you'll want something from you dated as close to April 5th 2016 as possible.