Yet another example of Riot not balancing things -- for money.
"Oh, yeah, we're nerfing CoC and then we'll look at Hecarim and Vi for changes in a couple months."
... yet, as is usual, that's not the issue. The issue is that they can both build a Triforce into full tank and still kill people faster than they can react, with low cooldowns and absurd base damage. Both are hyper mobile as well. Then, combine that with massive AoE damage making them clear like gods... yeah, it's JUST CoC that makes them strong. Totally.
But then, balance isn't really what you care about. Vi has a new skin soon, and Hecarim has a lot of skins he could sell, so you gotta keep them OP and FOTM for a while, milk all the money you can, and then either never nerf them again (despite their issues still being issues) or repeatedly make placebo nerfs that don't even impact their issues (remember Ashe? You nerfed everything but her Q (which is her issue), and when she stopped being popular, you stopped making placebo nerfs).
Never once did anyone complain about Vi or Hecarim having a shield from CoC. Many times though, I've seen complaints / complained about dying before their ults wear off, or being killed by a Q>AA>E (Vi) or an E>AA>Q>AA (Hec).
Sure would be nice to have a company that gave a fuck about their game beyond how much money it makes them.