Mass Effect is widely regarded by critics and players to be one of the greatest video game trilogies of all time, and one of the reasons for that is its fantastic worldbuilding and lore. The exploration and dive into alien civilizations is one of the best parts of the trilogy. While Shepard works for the human-led organizations Alliance and Cerberus, the majority of companions are aliens from across the galaxy.
There are many different species of aliens, such as the hanar, volus, elcor, and vorcha; despite the jokes about one day getting a vorcha romance, players don't expect to have any of these species as squad mates. Most of the species in the galaxy are on the table though, including the Council races and those recruited to the Normandy across the Mass Effect Trilogy. There has been one notable exclusion of an important species as a companion, and BioWare nearly included them in the iconic squad in Mass Effect 2.
The History of Batarians in Mass Effect
Batarians are a contentious group in Mass Effect: they're politically and socially isolated from the rest of the galaxy, their culture practices slavery, and there's a very high chance that Shepard's background includes a traumatizing experience with the batarians. The batarians were behind the attack on Mindoir where Shepard grew up if they had the Colonist background, and led the attacks on the Skyllian Verge where Shepard later earned their fame or notoriety. Since these attacks, all batarians have retreated to their home systems and are banned by their governments from leaving, and so all the batarians encountered in Mass Effect 2 are pirates and criminals.
Their bad history with humans makes them an unlikely choice as a companion for the Normandy, but Shepard's had weirder with a geth on board. Cut content from Mass Effect 2 revealed plans for a batarian companion who could have worked. Recruiting this batarian would have played into players' expectations of batarians by being tasked with hunting down a batarian terrorist, only to find a socially awkward geek with a flair for tech. Savvy players would note that this sounds a lot like one of the people on Garrus' mercenary crew; he describes his tech expert as a batarian who could "hack any system ever built", implying the concept for the Batarian Gearhead was repurposed into a throwaway line but one that added depth to Garrus' team.
The Story Behind Mass Effect's Squads
There are a number of reasons why the Batarian Gearhead character could have been cut. Firstly, there's all the conflict Shepard's had with the batarians that runs even deeper than their experience with the geth. On a more practical game design level, with Tali on board the Normandy there may not have been space for another awkward tech expert. Still, Mass Effect 4 should take the opportunity to embrace a batarian companion, especially one that goes against the stereotypes.
With most of their species wiped out thanks to being the first group of people harvested by the Mass Effect Reapers, a batarian perspective on the team would be more compelling and important than ever before. This perspective would also add depth to a species that desperately needs it; unlike the vorcha, batarians are clearly intelligent individuals who aren't confined to a singular stereotype, yet there's never an opportunity to dig deeper. By the time Mass Effect 3 rolls around, most batarians are dead.
It's highly likely the player character will be a human, whether or not Shepard is the protagonist of Mass Effect 4, and a batarian squad mate would bring interesting conflict, dynamics, and new lore to the story. Mass Effect's overall message is all about diversity. To continue to exclude the batarians as squad mates would be a pity considering the storytelling potential they have moving forward in Mass Effect 4.
Mass Effect 4 is in development.