The skill advantage is why you make a constrained list from your champ pool, but within the constrained list, matchup considerations can and should loom large. Which is why I like starting this kind of conversation on my list.
As for Reck's suggestions: Yeah, I can see the value of a true bruiser but keeping Nasus on standby for specifically needing a clock. (It helps I don't really need to keep my Nasus mechanics "warmed up" - mechanically he's probably my single strongest champ.) Vi is fun and I get two for one value running her top and jungle. Galio does enough Swain doesn't that I don't want to fully replace Galio with Swain, but it is probably fair to play Swain primary and keep Galio as a swap I practice less, especially since part of his appeal is how stupid easy it is to hit Smite anyway. (My Galio mechanics chiefly consist of taking the skillshot the size of a golf ball and using it on enemies.)
So pretty much I agree with everything, aside from swapping Ken for Liss. And that's not because I think Kennen is flat better or anything - I just don't go mid often, as I said, and so I don't want to dump a lot of skill investment into Lissandra when Ken is both fine and goes top well too. Lissandra IS super fun and if I wanted to always call mid I'd probably grab her.
So maybe something like this, where the parens swaps are champs I only pick into known factors:
Top
: Vladimir, Vi, (Nasus)Mid:
Swain, Yasuo, (Galio)Jungle
Amumu, Vi, (Volibear)Bot:
Graves, EzrealSupport:
Leona, Janna, (Nami)All-Lanes Wildcard:
KennenSeems like a decent compromise between depth and breadth. I'd need to drill my Vi and Yasuo a lot but the others will just take occasional refreshers. Also this would be a hilarious excuse to learn support/jungle kennen.
