Anyone else think this idea should be played with more? Seems like it makes it harder for in-universe characters to discover who's beneath the cowl, since the heroic identity can operate at the same time as two of the secret identities. It's probably also easier to maintain consistent patrols, since two of the three can take a night or two off.
I know we've seen this sort of happen when a character "dies" and someone else later takes up the mantle or when there are two or more people with the same superhero name, but having more than one person simultaneously trying to give the impression of being the same person (not just using the same name) doesn't really happen much. The only example I can think of is the Batwomen above.