I suspect that google has a profile of how a site naturally gets linked to. These are quick guesses but perhaps 20% of anchor text are domain name, 10% 'click here' and 50% a keyword phrase with the remainder being various other keywords. To have all links in the same I guess would be suspicious. (These % may be totally wrong!)
Reproducing a 'natural' linking profile could be a good ambition for any seo! :)
A few variations and broad match terms linking to you must be a good idea to target a range of on theme searches. Each variation may support your main target keyword, which should be the most common.e.g.
30% 'widgets' 10% 'red widgets' 5% blue widgets 5% green widgets 5% Get new widgets here 5% broad match 20% domain name
Perhaps the most important thing is that any keyword links are on theme and match your text.