At this point in the game's life, I think that we can all safely agree that it is extremely easy to read Mirage's decoys when sent out. Always imitating whatever action the player was doing in a straight line, or standing still, and always a hologram of Mirage.
I think a good way to give Mirage's tactical ability a little more spice would be for it to be a different legend besides Mirage every time, following some sort of RNG logic either pooling from all legends or the other legends on your team. That way, the decoy would have a higher chance of bamboozling enemies because it'll be harder to identify as a decoy or another player.
Thoughts? I believe that this would go against some of the currently defined lore for the game, but this would make Mirage a little more viable, especially when including the fact that his ultimate and passive are two of the worst in the game in their current stage.