Both of u need to understand something.
Current system and system with matchmaking since the beggining of this game is ELO based. So, win/loss calculation.
If I am in team that is weaker which happened a lot of times, thats a because i have far more wins compared to that 2-3 generals in other team.
Second, there is no search time so u just enter that room. Anyone can enter in it,regardless of rank or time of the match (cheers for all defeat screens when I just spawned).
Now, to the topic of overall rank. Rank/xp is something that u earn by playing. So is game experience. U are not playing Tank better because u upgraded it and suddenly figured out how to play the game. More like, u figured out and upgraded in similar time. Rank doesn't matter really, it's how much is someone interested to learn the game. IN any game u gonna find ppl being higher rank than u but playing like plebs.
That G2 and G3 from ss are fairly 'new' players in term of time and very different ally/enemy team that was around when i played. Aka these 2 played mainly blaster if I'm not mistaken, which isn't really skilled class, so when they switch to some other class that requires a bit more than half brain to play, they might not gonna show much/go along with ur expectations.
Last thing, win/loss. Sitting on capture point is one thing, another thing is sitting everywhere but not on point and just leaving it for the enemy team without even trying to re-cap it. These players are known as 'kdr' players or to translate that - ppl who don't really care will they win or lose, they are just there to have as much kills as they can and run when they are about to get killed. Then there are simple games for ppl like me who really don't care from time to time to cap, just to have some fun.