I totally agree, as a PRX fan (sadge), I think their limited agent pool is holding them back. Another reason I think is holding them back, is that their whole team identity and overall mentality is being the "silly" and "funny" team, like yes, you guys can and do play wackass comps and all that but, there are reasons why meta team comps are meta. An example is the Copenhagen finals 2 years ago, alecks had told the team to quote "go full meme style," that's what caused the breeze comp in the final map.
f0rsaken and davai have both said they they cannot play Sova and Cypher to the highest of levels, and as those 2 agents are meta and vital on maps like Ascent and Split, it is hindering them. I think having something play Jett and then a flex init is probably the best choice for him.
jingg, my boy, I love him and his is legit one of the best Raze players to ever touch the agent, but he needs to learn other agents. He plays Raze and then maybe the one off Icebox Sage game, but other than that, pure Raze. For the team, he would need to learn senti, mainly cypher as stated before, they don't really have someone that can play him to the highest level, but nonetheless, senti.
I think the best roles for the team would be:
mindfreak: hard smokes
davai: flex initiator/smoke
f0rsaken: flex
something: jett/initiator flex
jingg: raze/sentinel flex
The jump from duelist to sentinel might be a big jump for jingg, but they have made him play Deadlock once, so maybe they're experimenting on that. He could try and learn from f0rsaken or davai, as they've both played sentinel to high levels.