Hecarim's Current State
After the nerfs to Homeguard and TP, Hecarim's win rate has diminished. Plus the recent unnecessary nerf to his passive, his win rate has been sitting at a pathetic win rate of 45%.
What makes him really weak right now is that there are very few items that work well on him. Thanks to Ezreal, Iceborn Gauntlet was nerfed and now it's just a noob trap, since Hec's E just knocks targets out the slow zone, making him extremely easy to kite.
IMO: I think Hecarim deserve a couple buffs, to get him back on his hooves again. Adjust his passive ratio a bit, make his E last longer or faster (right now Rammus' Q is better than Hec's in every way), make his ult go faster. I am not expert in balancing