Link text inclusive or exact?

[freehits]

When inbound linking we always set up the same text web-wide for the same page. And we try to match that incoming link text to the title and H1 tags whenever possible.

The question is does a link of
'rent to own charlotte homes'

match with
'rent to own charlotte'

Do we have aneed for every inbound to have an exact keyword match to get the full benefit or is the inbound link judged by words contained total or words contained in the present order.

EX: a google bombing campaign for "harry potter book" was to have 20,000 IBL all with different sentences of 3-10 words with Harry potter book in the anchor somewhere in that order, is this the same benefit as simply harry potter book.

Is it in our best benefit to make sure every link targets the exact same text with no before or after text?

I read rumors of this could touch on what is triggering sandbox issues when too many links are identical and that smells like automated.

My current results always lean toward EXACT same anchor text is key, but before i choose to vary it slightly here and there I want to hear more from WPW