In my opinion, I don't think your products are over the top. I don't see the need to mix conditioners unless you are trying to use them up or can't find the right combo in one.
When you say smoothing product, what is that? Your moisturizer? I don't see a moisturizer listed.
I have a very solid regimen that never changes.
I have my clarifying shampoo, moisturizing shampoo, deep conditioner (moisturizing), leave-in, heat protectant and a moisturizer.
I do have some special treatment products under the sink that I use from time to time, like a protein treatment and oils. Those are "as needed" things and not used all the time.
Oh, in my shower I also have a separate conditioner for slip. Sometimes when I rinse out my deep conditioner, my hair does not have the slip I like so I do a rinse with a proven conditioner for slip. I notice this phenomenon as I get closer to touchup time.
It may seem like a lot for some, but after much experimentation, I find that when one part of my haircare equation is removed, things don't go the way I want them to in styling and moisture retention between shampoos.
I think your product list is common. But, if you do prefer to narrow it down, your leave-in could double as a moisturizer/smoother. You could also find one good conditioner that you like without having to mix 3.