Absolutely right!
The alternative, if like me you have two neighbours who freely admit they know Jack about what to do, is to set up the wireless routers for them and consider such channel spacing as part of the work.
Shhh. A third house is also within range, but the current elderly owner has no WiFi. The previous owner did, but with a SSID left at the default of NETGEAR I had everything I needed to know to find out what channel they were using without recourse to a sniffer, ahem.