AdAway uses hosts-based blocking, it is less precise than the one in Bromite but more powerful because it can block access also of any app; it is very similar to an IP-based firewall.

For most users Bromite itself will be sufficient; I see you are also using the SystemWebView, so I don't think you need to run AdAway, you can save CPU usage and battery without it. I suggest you try disabling/uninstalling it, there should be no difference in your experience.