It depends. Context is key. Curtain or shower door? How large is the shower? Floor plan with dimensions would help us help you.

We need to see a plan - you can even draw a simple one on paper, to know what you are talking about. When you say back wall it makes me think someone has to lean all the way over the tub to turn the shower on. Is that accurate? If so, not a good idea.

Windows are bad news in a shower, so that probably shouldn't exist, first of all. But a layout needs to be shown for all of this.

We are installing a tub/shower combo with a Hydrosystems Sydney tub, 60x32. with a shower curtain. The bathroom is 96"x80" - You walk into the bathroom and the window is on the 80" wall straight ahead. The vanity and toilet are on the left side wall (96" wall.) The tub/shower combo is on the right side wall (96" wall.) Facing the current shower/tub on the right side wall, the fixtures (valves) are on the 80" wall closest to the entry, from original construction.)

. My husband wants to move them to the 32-inch opposite side wall of the tub, adjacent to the window, not inside the shower/tub combo on the 60-inch wall. I like the current location. The window is not located inside the shower. It's in the middle of the far wall between the toilet and tub. (I'm not sure how to accurately identify the location of fixtures in contractor terms.) thanks for suggestions.

My husband has the drawing - I'll share it when I can...

I am not following your description ...

The HydroSystems Sydney tub is an alcove tub with flanges on three sides and the drain at one end (buyer chooses left-side or right-side drain) -- "alcove" means that the tub needs to fit against walls on three of its four sides.

I am picturing one end of the existing tub against the wall next to the room entry with the tub drain on the RHS. Is there a 32-inch wide partition (full wall or pony wall) at the opposite end of the existing tub?

Are you saying that you want the new tub to also have the drain and tub spout on the RHS, but that Mr. JAS wants the shower valve to be on the LHS, on the partition on the LHS of the tub?

Or, are you saying that Mr. JAS wants all the plumbing and the drain for the tub/shower combo to be on the LHS?

It sounds like you are saying that Mr. JAS wants the shower valve to be on the same wall as the window. That makes no sense, as the valve would be unreachable by the bather in the tub/shower enclosure.

Hot mess express with a high chance of leaks. Especially if DIY. There are zero people with abilities on board. Can’t even draw a stick figure diagram. Jeesh.