@twoamoebas,

TP-Link has not sold individual powerline adapters in the US for many years now; instead, the adapters were developed to be used for both purposes, receiving and sending data. While the features may differ between the devices, such as having a Wi-Fi connection, they will all connect into the Powerline network. Adding 3 Wi-Fi Powerline connections may be disadvantageous to your setup as it may cause a lot of interference between nodes, at the point of having this many nodes, I would recommend looking at potential alternatives such as mesh. I would recommend looking into the OneMesh technology that is on your devices, as this would allow the networks created by the nodes to create one mesh network.

You can also DaisyChain connections that are connected in a onemesh configuration, potentially allowing wireless backhauls or the use of Range Extenders to create the mesh. If you are still looking to maintain the powerline backhaul, TP-Link's Powerline devices are designed to be used with any device supporting the same standard(HomePlugAV2)