I think ultimately it comes down to this.
No matter the algorithm, if there are only braindead people playing (I consider myself one sadly) it's more than likely that one would get matched to them.
I am bad at the game. I do not try to pretend I am good.
So my expectation based on my skill is that I should oscillate around level 10-13 with soviets. Not plummet to level 4 in a week and never be able to recover.
If I make maxims, I am strongest but eventually will get run over by infantry if my partners are not good.
If I make cons or penals I will have a K/D ratio of .18 and we will lose badly. My infantry never does damage. Ever. I had a penal squad next to a guys cons wiping some pinned units and he got all of the kills. I barely even had any damage. Penals - 0, Cons - 5. So a 240 mp unit vastly outperforms a 300 mp unit? Makes sense. And if there is an MG within 50 meters my units will be insta-pinned.
If I have a mate that makes MGs I will go sniper and we usually do very well.
So with this knowledge and anecdotal data stored away, I can understand floating around Level mid 11s or low 12s. I would be totally fine with that.
I would also like to add that I tend to play the worst factions. You do not learn anything about what is wrong with the game state by playing the easy to win factions or smashing noobs with premades.