Yes, I've outwaited problems in the past but this is different when I'm not at home and lights are on, etc. Do you mean to suggest I buy a google device and also have it connected to all of my devices like Alexa? Can you elaborate on how that would work, having a given device 'connected' to Alexa and Google? I didn't know you could do that.
unless you are using amazon branded smart devices (bulbs, smartplugs, thermstate, etc), then yes, set one device up just like you did with alexa. There will not be any type of conflict between the two. You can use the same smart device accounts to link your devices. For example, you can use the same Hue account for both. When you set up google, forget you have alexa. once you have it setup, then you have your backup.
One other option, you can give it a try without purchasing a google device. Just setup the google home app and give it a go.
I actually have a full setup of both google and alexa. I prefer alexa but I do use google sometimes. It comes in handy when amazon is having problems or, as I said, when troubleshooting. When I get smart devices, I will get the ones that will work with both systems, though I do have some that will only work with alexa. Who knows when amazon might decide to lock my account or they get on my last nerve with the forced sponsored ads and other unwanted content.
Anyway, I think it is something that is worth considering.