I am making this because I‘m annoyed with low gold rated queue. Here’s my hot take on strategy, feel free to expand and correct in the comments.

The roles:

-entry fragging

Entry fraggers are effectively suicide bombers. Pushing in ahead of everyone, they create pressure and confusion, and open room on a site for their team to push. Exceptionally suited is any unit that can set itself up for success, such as Duelists and Initiators, particularly Breach and Skye. Controllers can take over if necessary, but are less suitable and sacrifice too much value if they die. If this is you, screw your K/D. Care about K+A /D because you will die, and you have to be refragged.

-support

Second on site, supporters use their utility to set up and refrag entryfraggers. They usually guard the spike and follow the EF at a safe distance. This role can be played by Initiators and Controllers. The latter are more easily suited, but optimally you want both. Supports, despite their name, often have the best K/D because they refrag and play slow, setting the pace of the round with their utility.

-splitpushers

Splitpushers separate themselves from their team and usually push the other site on their own. They will play aggressively to cause a diversion, or slowly to flank and rotate behind the defenders. This role is mostly played by Duelists, but both Initiators and controllers can get the job done. Note that you shouldn’t split every round, or it will become easy to read and you will put yourself at a disadvantage.

-sentinels

Sentinels are in a bad spot for sitepush. Their utility is less useful for this, and requires setup which is risky during a push. On the other hand, it’s incredibly valuable post-plant. Your best bet is to push with the support and refrag while playing slow, save yourself for after the push.

An example:

Imagine a take on Bind A site. Omen smokes heaven and U-Hall, while Reyna flashes into the open from showers, Breach flashes into right side cubby from Boxes and runs on site, with Sage following to wall APC to cubby and Omen blinding and pushing into lamps, while Raze rotates from a now open B site through CT, to catch off guard the defenders who have been forced int playing retake.

Entryfragger: Breach

Support: Omen, Reyna, Sage

Splitpusher: Raze

You don’t need to balance team comp between ingane classes, but everyone needs to know and play their role.