Broadly speaking, it should work. I'm hedging what I write here, because I know there have been SOME forum members who found that the CO for one or other visa asked for extra copies of some things, so I think it's advisable to keep copies of whatever you send so you can send more if necessary, while saying, 'The original is with INZ (whichever office).'
Here
https://www.google.co.uk/#q=site:enz...tnership+proof are a whole selection of forum threads about evidence of partnership, to give you more food for thought. What you're aiming to do,
particularly (even if you're a couple whose joint history goes back years), is show plainly with very solid proof that you were living together 12 months before your application went in, and give say, three proofs that you were still together for each passing week. Yes, overkill is good! INZ COs work from a check-list, and as far as partnership for residence is concerned, they are required to look most carefully at the year leading up to the application.