I got interior shutters on my study window (other windows too), it is my first time having them. Previously had faux wood blinds. These are real wood shutters with the very large louvres, and I just absolutely love them. Cannot believe I ever went without them. They let in lots of light. The larger the louvre the more light they let in. And of course you can open them like a door so that's total light when you want it. They are so superior to blinds in all ways, just add beauty and value to the room.

Mine are full length, not split horizontally, so cannot speak to the horizontally split ones.

My shutters are like french doors on the large windows. Two shutters per window. On the regular sized window, I have one shutter. But on this subject, one thing to be aware of that I found out only through a mistake. My shutter guy's measurer was to call and set up an appointment when I got a cold call from another shutter company, mistook it for him, and invited them over only to find out two hours of sales pitch later that it was the wrong company. Anyway, this wrong company was pushing faux wood shutters, and saying I needed FOUR shutters on each large window. That would be a post down the center of the window vertically, and then a pair of shutters on the left, and a pair on the right. This would let in a LOT less light because of the post, because of the extra framing around the individual (smaller) shutters. He was pushing this so hard as though it would be a disaster if I didn't get that. Well, when I finally straightened out the mistake and talked to my regular shutter guy, come to find out this may be necessary with the faux woods because it's poly and that's very heavy. But the real wood is much lighter, so you can go single shutter. It has been a year and not one single problem with my shutters.

I only have a slight idea of what shutterdogs are so can't help you there. But from what you say about the small window... I don't think you should go with a different sized shutter louvre if that's what you're saying. I couldn't quite tell.

Hope that helps.

Shutter dogs are the rotating holdbacks that keep hinged exterior shutters back when they are open. Here is a link to the typical ones, and some others.
Unless your shutters are hinged on, you probably shouldn't use them, if you want architectural consistency.

Here is a link that might be useful: Shutter dogs

Thanks for your responses. Yes, bigdoglover, I meant that the shutters on the smaller window would be shorter, but the louvres would be the same as on the larger windows. Sorry I wasn't more clear on that point. And if I use shutter dogs, I would invest in hinged shutters. I know exactly what you are saying, bronwynsmom, and architectural consistency is one of my reasons for asking these questions.
So far, my preference is for wood shutters, both indoor and exterior. and now maybe full length and with larger louvres.
Great to get help from you guys, and I'm feeling less like a shutter newbie now.