Shader alpha value consistent with all transparent objects

Hi!

I have been recently learning to write shaders. I want to achieve effect like in the image, but I dont really know how to do that. I was trying to make a pass with blend options in a surface shader, with no luck.

I want a transparent, unlit surface shader with consistent alpha on all overlapping transparent objects. Is it possible? And I need the surface type, because of other effects that are in this shader, that I have cut out for simplicity.

Shader code for reference:

 Shader "Custom/TransparentConstant" {
     Properties 
     {
         _ColorTint ("Main Color", Color) = (1,1,1,1)
     }
     SubShader 
     {
         Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
         LOD 200
         Pass
         {
             ZWrite on
             Lighting off 
             Blend  SrcAlpha OneMinusDstAlpha
         }
         CGPROGRAM
         #pragma surface surf Unlit alpha noambient nolightmap nodirlightmap novertexlights
         half4 LightingUnlit(SurfaceOutput s, half3 lightDir, half atten)
         { 
             return half4(s.Albedo, s.Alpha);    
         }
         float4 _ColorTint; 
         struct Input {
             float4 color : COLOR;
         };
         void surf (Input IN, inout SurfaceOutput o) {
             o.Albedo = _ColorTint;
             o.Alpha = _ColorTint.a;

         }
         ENDCG
     }
     Fallback "Transparent/VertexLit"
 }