@burnzey91 Eh, if they properly matchmaked teams, there shouldn't be a leaver issue.
I still think filling in the missing player would be a good idea, except the player entering the game would get a prompt like: "You're about to join a game in-progress" and it would tell the player the arena score, asking them if they want to join the game.
I don't think buffing damage, reducing incoming damage, and changing shop is the way to go, simply because people would have teammates leave on purpose, and then suddenly the trio team can't do anything about the duo team, as the duo team can just run R-99's and other strong guns like the EVA.
Also, even if they did do that, you won't be able to benifit from it, because most "leavers" Alt + F4. Which, if you don't know, crashes the current window and closes it. So, players would close the game and walk away. They don't "leave" the actual match until 10 minutes later, due to the game giving them a chance to reconnect. As someone who Alt + F4'ed once, because it was absolutely pointless (terrible teammates who cannot aim and were toxic, VS smurphs), I can confirm that Alt + F4ing gives ZERO punishments. Which, if they're going to have a penalty, it needs to be implemented correctly. You can't Alt + F4 in normal ranked (that I know of), as it punishes you for things like dashboarding.