So here's the thing. You're right, it is unlikely to be a slow ping issue. However, if my memory serves me correctly, hub discovery is dependent on multicast. And I am unsure if multicast is working over the various segments of your home network, especially on segments that rely on MoCA.
If this is a multicast issue, then Hub Mesh is not the right solution for your needs. You should use HubConnect instead.
I'm tagging @csteele - if you go the HubConnect route, he is the best person to guide you.
Edit: FWIW, I used HubConnect for two years before Hub Mesh became available. HubConnect is very easy to setup (not as easy as Hub Mesh), but it is just as responsive and supports the same plethora of device types as Hub Mesh.
