Three into one

The problem with a triptych is to have all three paintings looking like they are part of the whole - hopefully style and pallette will be enough to tie them together, but this is the first time I have tried something like this so I still have a lot of things to decide. Does it matter that the third picture is zoomed in a little more than the first? Will it throw the balance off? Do I paint the two close-ups at the same time or individually? It might be easier to match colours if I do everything simultaneously but...I'm a professional! I'm sure I can reproduce any colour I need to so I think it is more sensible to paint them individually - especially as they have different moods. I now cannot get back down to the studio until Sunday - then on Tuesday I finally get to take the rest of my furniture down there and the studio will be complete. Finally - after about three or four months! I can't wait.