I'm more than a little confused, and don't know why, if it does, this change should affect the China hutches? Do you have a layout you could post? What is the purpose of the tall cabinet?

Do you have enough counterspace for things you want to keep out...
Coffee maker? Toaster oven? Cookie jar? Fruit bowl? Blender? Mixer? etc, etc. Because, just looking at space around the stove for prep and cooking activities, especially if the island is located to serve you well there, it looks like you have enough with the 25".

When you make one change, it affects so many other things, so it's easy to forget something else that was important to you when you decided this layout in the first place. I can't begin to guess what that might be, but it's dangerous to make sudden, last minute decisions without enough time to think it ALL the way through.

My first thought, for perspective if nothing else, is that to get really good design bang from symmetry, it needs to be contained in one view. Otherwise, even if personally pleasing, it may not be worth the cost of the tradeoffs to get it.

The fronts of the two china cabinets will never be in the same view--except when looking into the kitchen, from which vantage point--again--only the ends and foreshortened views of their fronts will show. They will create a symmetrical opening into the kitchen if their side panels are the same, with any lack of symmetry in their fronts largely unnoticed.

The stove wall itself is not on the main view into the kitchen. Even when standing more to the right of the opening, that wall will be foreshortened visually, so any changes in layout there, nice already, might as well be decided by function.
I haven't drawn pix to see which of your options, existing or change, I'd prefer, but I think they'd both function well and look good. I like your hood and exposed flue a lot, by the way. In fact, I like the whole thing. It's really going to be good.

Regarding the 25", though, it is enough if it's enough for YOU. I really recommend you grab your pots and pans, set up some boxes, and set to "work" in your kitchen to discover that personal answer.

25" is plenty. If it were your only prep space in the kitchen, I'd say it's not enough, but you have that whole island one step away. You're fine and you should lose sleep over something else. Post a picture when the marble is in!!!

OT, but will you be mixing rift oak and white cabinets?
I'm doing something similar and wondering what finish you've used on the oak...could there be a hint of gray in it...or are they natural?

Ok, my decision is made. My sweet dh said "that's a good idea" when I told him I wanted to move the cabinet. He was probably thinking "are you crazy?"
I am going to move the tall cabinet 10" to the left to make room for a base cab. making the counter to the left of range 35" wide. My marble has already been cut, but i'm sure I can find a piece to match. Luckily my two china style cabs have not been made yet.
Lisa, I think my painter was about to fire me over staining the oak, I wanted too many samples, finally I chose one, telling him, don't worry, I will hate it for a while then I will be fine with it. It's not your fault.
I was going for a driftwood look and considered doing a ceruse or white lead finish, but that is a longer process than I wanted to go through with marble coming on Monday. So I ended up with a slightly gray look. They were stained with coffee stain, then gray stain. I obsessed over the color I wanted, going from dark, then light, then natural, then gray. Overall I like it, and will post a photo after the finish coat. I can't believe I'm almost done with this remodel and very nervous about the final outcome, it's very eclectic.

Yes, we're going back and forth with the cabinet maker as well...really hard to get the right shade of gray.
I think your decision to increase the cabinet length next to the stive is a good one.

Right now the counter to the left of the stove is way too small. I had one like that and it just was not a functional work space.

Again a little OT, but what will you be doing for counters and flooring? Like you I'm having more than a little anxiety in planning a kitchen using finishes I haven't actually seen anyone else use. In my mind it will be lovely...but so anxious.

My main concern on the width of the counter to the left of the sink (I think I will give it a name so I don't have to keep typing that) is that the range hood did not look balanced in the space. I tend to err on the side of form over function.
Lisa, I have no idea how I came up with my finishes, I think I fell in love with them individually and am hoping they all look good together. Dumb, I know.
And, as each item is installed it looks just a little bit different than I imagined.
So, my floor is limestone, base cabinets are painted BM Natural Cream, pantry cab, refrigerator cab and two china cabinets are all stained rift cut white oak and the counters are 2cm Calacata Oro, Island will be a industrial wrought iron base with a 2" piece of regular white oak, maybe distressed a bit. The window in the kitchen is three french casements painted black (I really wanted steel framed windows) with cremone bolts.
Here is my floor, it's showing yellow/orange in the photo, but is really a gray brown color.

Have you seen this kitchen, it's gorgeous! I think I've seen every kitchen with rift cut oak on the internet.