Extenders don't work like that. 2 antennas are used for 2.4GHz and the other two are used for 5GHz. Each pair is used for both transmitting and receiving.
So both sets of antenna (2 on 2. 4ghz and 2 on 5ghz) communicate with both the router at the house AND devices connected to the network? It's not 2 antennas dedicated for the devices to work from and 2 for communications to the router??