We have now looked at both sides of the argument over whether superheroes should have a secret identity or a public persona. There are definitely advantages to both. Some can be beneficial but there are also disadvantages that can be problematic or deadly.
Deciding whether or not to have and maintain a secret identity could be the biggest decision a superhero can make. Depending on the choice, it can begin to define who a superhero is and how they operate. It can also play a factor in what type of costume the hero has, if they even bother to have one.
There have been some exceptions but, for the most part, once an identity is revealed, there's no turning back.
There is another option besides having a secret identity or not having a secret identity. If a superhero was creative enough, they could consider the possibility of having more than one secret identity.
It might sound crazy. Trying to balance a regular identity along with a superhero one could be more than most people could handle. Having different identities could have many benefits.
The first that comes to mind is Moon Knight. Marc Spector was a former U.S. Marine-turned-mercenary that was reborn by the Egyptian God of Vengeance, Khonshu. Marc Spector was who his true identity but it might've been hard for a former merc to find a place and normal life in New York City. With the identity of billionaire Steven Grant, Moon Knight had access to high profile individuals as well as a way to invest and generate money in order to fund his crusade against crime.
It's possible he could gain information at high society parties but he also had another identity that gave him access to street level information. As Jake Lockley, the cab driver, he was out there and built a trust among different individuals. Now Moon Knight is using his Marc Spector identity to act as a Hollywood producer.
With essentially three civilian identities, it would be hard to pin down who Moon Knight really was. If his enemies ever unmasked him or discovered one of his identities, he could sacrifice one and keep the others. When he was being hunted down by Norman Osborn's Thunderbolts and the Commission on Superhuman Activities, 'Marc Spector' was killed off when Moon Knight faked his death (he later turned up in Mexico with the Jake Lockley identity as his main one.
The idea can also be flipped around. A superhero could benefit from having more than one superhero identity. How many times has someone like Spider-Man or Daredevil been noted as patrolling the same area? If a hero had different costumes and names, it wouldn't feel like the hero seen all the time must live in that area.
During the Identity Crisis storyline (in 1998), Spider-Man actually created FOUR other costumed personas. The reason Spider-Man created new identities wasn't because he was actually having an identity crisis. He was framed by Norman Osborn and Trapster for killing a thug named Joey Z. There was a five million dollar bounty placed on his head.
Spider-Man couldn't fight crime without everyone gunning for him, trying to claim the bounty. His solution was to create the other identities (which would later be used by others as members of Slingers).
This does give a hero some flexibility. Too often when a villain sees the familiar hero coming along, they know how to prepare for their attack. If they know all of Spider-Man's abilities, they could have a plan on how to avoid being defeated right away (similar to how Batman has a plan to take on everyone).
A superhero with multiple identities could patrol their neighborhood without giving away that they live nearby. They could even change up their fighting tactics.
Continuing to use Spider-Man as an example, when Aunt May was shot, Spidey was extremely ticked off. Instead of putting on his red and blue suit, he put his black suit on to show he was dark and angry. If a hero wanted to, they could create a more violent persona that could have more extreme fighting techniques for those really scummy villains that need more than just being captured and delivered to the police. This way, it doesn't tarnish their wholesome image, if they have one.
Even Batman has used more than one identity. For years Batman has used the Matches Malone identity to gather intel among the criminal and low-life. Taking the guise of a small time criminal, Batman had access to places he couldn't exactly go dressed as the Dark Knight. He could uncover information about the bigger criminals in town without tipping them off.
Batman recently created another superhero-type persona as well. When he returned from the dead after his confrontation with Darkseid, he wasn't quite sure where he fit in and wanted to know how the others in the Bat-family were doing without him. Using a new tech-based suit, as the Insider, he confronted each of his former sidekicks and apprentices to test how far they've come.
This was something he could have done as Batman but with a different identity, he could attack and confront them with a level of anonymity he wouldn't be allowed otherwise.
It might be hard enough for a hero to juggle their superhero identity and civilian one. For a superhero to even consider trying to maintain several identities to could enough to drive them insane (cough, Moon Knight, cough). Keeping a secret identity is almost like a challenging game and having multiple ones will give heroes an edge, regardless if they're civilian or superhero ones.