@ Tedster - I didnt write that on a whim, I have been mulling this for some time and experienced it by experiment shall we say. Perhaps the term limit is over the top, but there is a ranking of terms for a page - if stronger for one phrase will weaken another. That doesn't mean a page cannot rank well for for multiple phrases, but there is something in this; and it makes sense after all.
If the page is especially dominant maybe the effect will not be seen much, but if not quite #1 on all phrases, this does occur - boost one phrase and lose a bit on the others. I've seen it over time; I don't know if it's a new thing (probably not) but surprised not to see this mentioned previously (as far as I know, but I'm quite new to SEO).
I've shared what I found and feel i did the right thing; if it is ignored so only I benefit that's not a bad thing ;)