Your breakfast table needs chairs with narrower seats. The big dining room chairs are not going to fit under the breakfast table- even less of a fit than the current chairs.

The gray chairs are narrower and the back is lower in height than the brown chairs.

See pic

Thanks for photo; that's a surprising difference. Try putting the gray chairs around the breakfast table for a week or two to see how they work for you.

You could get the gray style in easily cleaned faux leather if available. White or a light color for the breakfast chairs.

My thoughts are that it looks more interesting and personal to have different chairs at different tables. Having the same ones with such similar tables in a modern setting like this makes me think of a hotel, restaurant, boardroom, etc.

But that’s just me. If you love them, do what makes you happy.

Beautiful big windows and view!

I love having the same chairs at the dining and breakfast table. At least in our smaller house, it makes the spaces feel more cohesive. And it makes it easy to swap chairs around--when we entertain, we expand the dining table, use all the chairs there, and use the breakfast table for buffet service. I do like apple-pie's idea though of getting the breakfast chairs in a different color.

That's similar to what I was thinking. If you can't get the same chair get something that will look well mixed in the dining room for larger groups. Maybe buy two captains chairs for the heads of the table and then use those two in the breakfast area.