Yes, that's possible, but you also have to consider that the AV600 devices have been on the market for a long time, and the data throughput rate in practice is not 600 Mbps, but perhaps more like 250 Mbps. And at the LAN connection it is 100 Mbps. So it's old technology.
You can simply use these sets together. All you have to do is connect other devices with the pair button.
Therefore, it is better to buy these sets. They have a higher transmission rate via Powerline and also offer fast 1 Gbit/s LAN on the adapter. They don't cost much more, but they are much better.
TP-Link Gigabit Kit TL-PA7017 KIT (1000Mbit/s)
An alternative would be a TP-Link Deco WLAN mesh system, which is available as an M4 3-piece set for about 150 or as an M5 for about 200; and each Deco Mesh WLAN device would then even have 2 x 1 Gbit/s LAN.
