Like, really. My main picks and top are Sion (against immobile) and Lissandra (against pesky mobile champs. All hail instant-cc!). What does Riot recommend me? Quinn top. Uhh what?
But it gets weirder. My current main jungle pick had been Taliyah (before the rylais nerf). Before I usually took Sion, because well, he's one of my best champs and not so bad in the jungle. Recommendation: Amumu. This is a bit more logical than toplane but still...
Midlane: my main there: Veigar, because I love massive burst damage. No matter how fed an enemy gets, if you can oneshot them they can't carry. Death is the best cc. What is the recommendation? One of the most iconic DoT users: Malzahar. Ehhh... why?!
Adc: Not my best role, but I managed to achieve mastery rank 6 with Miss Fortune adc. Solid aoe damage and lanebully-power that can carry you through the early game. What do i get? Freaking Kalista. Until that point I even forgot that champ exists because I see her maybe once in season 6. Not sure if I ever played her or any other champ that plays remotely like her.
And last but not least... Support. I rarely do it, but when I have to fill I usually pick Nami or Soraka, sometimes Veigar if I feel trolly. If my team really needs a tank, I pick Taric, but only because he's in the "can save your adc even if they only play with quarter a brain"-category as the AP supports. And what thinks Riot that I should totally try out? Poppy Support. Like... what? How does this in absolutely any way go with my playstyle?!
All in all, it just feels so incredibly random.