Small energy providers in Germany have joined forces to launch an assault on RWE and E.On, as the pairing continues to progress with plans for a massive asset swap which could transform the energy market in the country. Led by electricity retailer Naturstrom, the group of 11 companies lodged a legal action with the European Court of Justice on Wednesday, appealing the deal – valued at $44 billion – saying it will restrict competition within the Germany market, “clearing the way for two national champions at the expense of medium sized companies.” The primary aim is to overturn the approval of the deal last September by the European and German regulator Bundeskartellamt, and essentially reverse the asset swap. The RWE-E.On…