Simulating GFL combat is a pain in the butt, even with the new "pause game → save formation → simulate ingame" feature (which not enough people are using), so there's external combat simulators. Except it's still a pain in the ass because every single bug needs to be carefully copied and hundreds of dolls tracked, so they all die after a few months and a new sucker writes a new one. Rinse and repeat.

Current state of the art is this javascript abomination that probably only runs on Windows, but lets you proxy the game itself to automatically use your actual doll lineups, and this somewhat outdated browser simulator that should work for all these people who keep browsing on Playstations and fridges. Expect both to literally die before the year is over, again, the links will probably be updated in that case.