Re: Am I missing something here?
Haven't looked at Debian 9 yet, but am I to understand that systemd is trying to replace bind 9 with some bastardised version?
No. systemd-resolved is an optional part of systemd and not included in Debian 9 by default.
If you are using bind9 then systemd is likely to be the least of your problems. Get a decent DNS package. I'd recommend unbound for a recursive resolver.