Moto G and nano-Sim adapter
I wouldn't recommend them as I did indeed damage pins in my S4 using one.
I am not sure about your carrier, but mine here (Vodafone) allow users to simply activate a new sim over the phone using their automatic customer help service.
I simply dial up, go to the activate new sim selection, enter the SIM card number of the sim I want to use and then it tells me it has done that. I end call, power up the device with that sim and hey presto now all my calls / cellular goes to that sim and my old one goes inactive.
To return back to the inactive one I do the same process,
It takes less time to do on the phone with the automated service than actually swapping out sims and messing with adapters.
Check your carriers automated customer support to see if they offer something similar. If they do, simply keep a blank sim in both phones and activate the one in whichever device you wish to use that day..