Just find a group for it. I like playing Mystery Heroes a lot so my MMR is quite high on it and sometimes finding decent teammates is a struggle since the matchmaking tends to throw master+ players together with platinum players to even things out and sometimes they go even lower/higher than that. The only way to eliminate this is to find a good group.
Once we had 4 really great Mystery Heroes players in our group and while our queue times sometimes went above 10 minutes our W/L ratio was something like 15-2. It’s crazy how good results you can get in Arcade by simply grouping up with proper players