Probably will be the most skill based achievement as players playing tournament mode are quite good. The mode consists of 3 rounds. In round 1 there will be a total of 8 teams. There will be 2 brackets bracket a and bracket b your team will need to be in the top 2 of your bracket to advance to the 2nd round where the top 2 teams from bracket a and b will advance. Round 2 will be similar to round 1 where the top 2 teams move to the next round However the last round will only be a 1v1 between the top teams of round 2.
As for team compensation I would recommend at least 1 or 2 mediums with healing and defibrillators and 1 heavy. Play the objectives and grab the cash box or camp the cash out areas.
There is also skill based matching in this mode and it's quite apparent as boosting this achievement will be tough since you will need at least 24. There is also a quitter penalty so be warned if you think you can use your alt account. I've gotten about 20 wins in this mode solo queueing and stacking in duos or trios have a lot more sbmm