OK that all makes sense now - thanks for clarifying. I've done some tweaking to certain pages today to see if/how they start performing differently, and once I get a feel for that I'll aim to roll out across the rest of the website. The tutorials were really useful too - wish I had found them sooner. I did actually use Moz for a while but actually found these snippets were more intuitive.
Fingers crossed for a brighter future!