Yeah, lacking an amaro, I feel like it might be a touch unbalanced.

That said, you could probably make a toned-down version at home. My wife commented recently that Dolin vermouth has some notes that are reminiscent of tomatoes, and they definitely show through when I make negronis with it. Gin, Campari, and Dolin, with the herbal garnish from this instead of an orange peel might work pretty well!