Here's an excellent article from the L.A. Times about Tommy's and all the wannabes. The interesting thing to me was Tommy's doesn't worry too much about them unless they really get too close to pretending to be the real thing. They see the imitation as flattery. Tom's #5 is mentioned.
In the South Bay, there's Tomboys which serves up a pretty good version of the Tommy's classic burger with chili - no beans, cheese, tomato, mustard, pickle & onions.
https://www.latimes.com/food/story/2...gers-knockoffs
L.A. Times