>>I overcome this problem by not taking on competing work.<<
WG... wise words. I'm amazed that there are marketing/SEO companies out there who sell themselves as specialists in a particular market area, opening themselves to potentially huge conflicts. If I've done a site in an area similar to that of a new client, I always let them know.
>>They all belong to the same parent company, but are run by individuals... my problem is coming up with fresh content on the same subject!!!<<
I was in this situation, and fairly recently... Actually, I'm still in it, as I'm submitting some of the individual companies, one by one, slowly, to the same categories in ODP.
In my situation, I was in fact unable, past a certain point, to come up with different words. The products and business model were exactly the same.
The parent company was quite content to have all the different sites battle it out for the same terms, but I found it hard to manage the project this way. What I had to do was to have the parent company marketing people make an arbritary decision about priorities for different phrases or products. I had to ask "who's #1 for red widgets, who's #2, who's #3... etc etc?" and ditto for blue widgets and green widgets and for custom gizmos... and I put the priorities in a spread sheet which I referred to frequently.
In titles and descriptions we then found ourselves hunting for different non-targeted adjectives to include in titles and descriptions, just to give these businesses some individuality in the SERPs and directories. I varied word order and emphasis as much as I could.
One of the most difficult parts of creating content was to keep the client marketing people from giving me identical copy for all the sites. I'd warned them going in that this was going to be a problem, but they didn't really get how big a problem until we were on about the third site.
The sites corresponded to brick and mortar locations, so in some cases location was a differentiator (is that a word?), but I had almost ten sites that all wanted the same location name.
ODP is taking long enough on listing the descriptions, which I'm submitting one by one, that I don't know, in fact, whether these non-targeted adjectives will make the descriptions look sufficiently different to get them in unedited.