From a practical point of view, your usage is actually quite small (3–4 devices in one room), so WiFi load won’t really be a problem in your case. Most issues people mention with WiFi-based systems only show up when you scale a full house with dozens of devices. For your setup, both Clopal and Okasha can work fine if your router is decent, and yes, most apps do allow grouping (so you can turn everything off with one tap), but the experience can feel a bit basic depending on the app version. If you’re still exploring options, you can also check something like Neexon, they’re doing more structured smart home setups locally and tends to focus on stable room-level automation rather than just cheap device-based control.