Would love your collective wisdom as I rework a bathroom. Please bear with me as I describe what we've got, and what we'd like to do.

The previous homeowners put in a large corner shower with Hansgrohe fixtures, installed in 1997. On one wall, there's a fixed showerhead, below that is a small stand alone lever that turns that shower on (and so controls volume), and then below that is the thermostatic trim "dial." On the adjacent wall, there is a hand-held shower on a slider bar and another small stand alone lever that turns that shower on; temperature for this shower is also controlled by the thermostatic "dial" on the other wall, some 4 feet away.

For the past 8 years we've been in the house, we've only used the hand-held shower; showering with the fixed shower head, we quickly learned, means no one else can take a shower afterward until the water heats up again. And it's not even a rain shower!

In reworking this bathroom, we are replacing the shower with an alcove tub (vintage cast iron) and shower. Initially, I thought I'd just get all new faucet components, because I'm not a huge fan of trim dials and slider bars--I'm more of hot/cold metal cross kind of gal, I guess. However, I see the convenience of being able to leave the water at a certain temperature, independent of turning on the shower or bath. Also, as I've shopped around, I've been amazed at how less hefty handles and levers seem to feel these days, and how expensive everything is in general.

Ideally, what I'd like to do is buy just a new showerhead and tub spout (plain, without diverter), and re-use the Hansgrohe thermostatic "dial"/valve and the two stand alone levers/valves, so that one lever turns on the shower and the other the bath., with the dial controlling the temperature of both. (Vertically, it would be showerhead, lever for turning on shower, thermostatic "dial", lever for turning on bath, tub spout).

Forgive me if this is a stupid question, but is this possible? Would it look weird? Also, is it even advisable, given the age of these components? Or because it might lock us into an atypical configuration?

Thanks in advance for any insight!