I'm surprised the "dominating group" is that large. There aren't a ton of _senior_ scientist out there (i.e. professors or researchers with the funding for graduate students and postdocs), and those are the people whose names appear most frequently. A senior scientist will probably have been doing research for years, have lots of projects going on at once, have many students and postdocs, have a number of collaborators, and the senior scientist's name will go on every paper produced by that group (even if it's as a middle author -- which means next to nothing). New guys will often want to collaborate with the big names, which means the big names get on even more papers. If you're working on your own (i.e. you don't have the funding to hire others), then you won't publish as frequently.
What did you expect? Why is this an issue?
A graduate student who has been working on a project for two years (and who should be working on a paper)