ELO is fundamentally flawed in team games and should never be used, but developers continue to misuse it because it is recognizable and “easy”. ELO only works correctly in 1v1 games.
Somebody’s ELO in a game like ToS or ToL would mean literally nothing. There is too much random chance and unbalanced distribution of power between the classes to provide an equal amount of influence for each game.
Newark suggests a simple +1 or -1 rating system which is only correct under the Law of Large Numbers theory. In reality, reaching your true ELO with this simple method would require an enormous amount of games. Likely thousands.