Well, you have 5 lights and 10 steps, I'd space them so they are spaced equally going up the staircase rise. Try hooking one up at night and see how high you have to go to get coverage for the area you want to light before you set them permanent.
You have 5, I would go with 6 . The two critical places for lighting is the transitions between steps and landings. This type of lights cast the light down so the top light will do little for the top landing and the bottom light on the lower landing will be shadowed by the first step.
Start with the first step and end with the upper landing and then one every other step. For height look at the recommended height of the maker or experiment with one. We don’t know your big plan but you could extend another in each direction on the landings at the same height as the last lights if you have a dark spot.
These lights are low voltage LEDs only the input is 120V but thre is a driver in each housing for that particular light as opposed the to the DEKOR lights which have one driver for a series of lights.
By the way, DEKOR was the first light I was considering, but I opted for these lights as I liked the look better. Each light emits 180 lumens which I've read is equivalent to a 20W incandescent.
Unfortunately I don't have the lights yet and I won't be able to get them before we pour tomorrow or on Saturday, so I'm trying to take a calculated risk with the placement.
Also, if the lights don't light up the stairs properly I can return them for a different style. Juno lights were another brand I was looking at.