They look perfectly spaced apart in all respects. The only issue I see is the possibility of knocking them askew or off if a person isn't careful when using the wall railing. If you can move each up an inch or two more, it would help reduce that possibility.

Don’t know If this helps, but this is the distance I used for mine.

Yours look like they are spaced evenly above the handrail? I tried that but then I couldn’t get them spaced equally part for some strange reason ugh

I agree that they are close to the railing. Maybe smaller artwork.