/loc/ - Local SEO

i've been trying to tighten up the service area radius for a client with three different branches because their reach is overlapping way too much in the suburbs. it feels like if i shrink the circles, i'm losing that organic visibility in the fringe zones where they actually have high margins. i tried adjusting the specific zip codes instead of just using a radius around the physical addresses but now the maps profile for the main office looks totally disconnected from the surrounding neighborhoods.
>the overlap is killing our conversion rate
it's like the algorithm sees the density and assumes we're everywhere so it doesn't bother showing the specific branch that's actually closer to the user. i've even tried removing the broad city names from the service area list to see if a more surgical approach works better. every time i update the settings, there's this weird lag where the visibility stays exactly the same for like four days before it drops off a cliff. does anyone know if google favors a specific way of defining these boundaries when you're dealing with heavy competition in those overlapping zones?