How can I render two transparent objects as one continuous object?

Question

I'm struggling with transparency right now to get two objects to overlap and work as one layer. Ideally I'd just have one big red field over the skybox but instead I have moments where the transparency adds up. Is there an effective way around this?

What I want it to look like (from all angles): https://i.stack.imgur.com/juojG.jpg

What it looks like (from the angle where you see them intersect): https://i.stack.imgur.com/v8VqW.jpg

Current shader code:

Shader "Mobile/Particles/BallShader" {
Properties {
    _Color("Main Color", Color) = (1,1,1,.1)
}

Category {
    Tags { "Queue"="Transparent" "RenderType"="Transparent" }
    Blend OneMinusDstColor One // Soft Additive
    Lighting Off ZWrite On
    ZTest LEqual

    SubShader {
        Color [_Color]
        Pass {
        }
    }
}
}

edit: Just got closer to solving things but without a real understanding of how. Unity's built in particles/additive already deals with this problem.