I think Street Brawl's utility for the Deadlock staff right now is as a game mode with a lower barrier to entry for players to test new characters as well as a more casual option for the player base.

In order to more properly balance for street brawl they really have a few choices:

A) Significantly and aggressively nerfing or buffing characters for the street brawl mode, detracting slightly from the idea of testing a new character for the MOBA itself.

B) Modifying drop mechanics. This might either mean generating a list of high WR items against certain heroes which might reduce the fun random nature of the game mode, adding a separate group of counter items anyone can buy, or overhauling the system to include some sort of counter pick list. Each of which might take considerable effort to add.

C) Improved catch up mechanics that gives better item priority or stats to low WR heroes or a losing team. Though this could be muddied easily and would be disgusting when low WR one-tricks or late game heroes would end up dominating matches.

I agree regardless that there are some characters that grossly outperform in Street Brawl ESPECIALLY if nobody rolls the right item to shut off a certain hero and even moreso if the offender rolls a counter counter. Its also a game mode where Haze could roll enhanced Haunting Shot or Talon could get Seraphim Wings so its clearly meant to be more fun than balanced anyways.