Kayn vs Talon- Riot?

I might just be bad at thinking these sorts of things through, so I would like some input on this.

Kalyn's shadowstep, at max level has a 13 second cooldown. With max cdr, that's about 6-7 seconds (when the ability can last 5-ish seconds itself). He doesn't put the terrain on cooldown at all, thus he can walk over it multiple times in a relatively short period of time. Has a 90 mana cost.

Talon's vault lets him jump over different terrain rapidly, but doesn't allow him to use the same terrain due to long terrain cooldowns. Has no mana cost.

I could very easily be missing a lot of valid information, but I want to make sure that Talon, and his identity as THE mid to late game roaming/terrain-bypassing/hyper-mobile assassin isn't being stolen from him by the new guy. I personally find it silly how Kayn isn't gated by terrain cooldowns, but Talon is (and by very large ones at that)....am I crazy? XD

Is Kayn's shadowstep ability encroaching on Talon's identity?

(another reason I'm asking these questions is because I have a Talon bias, and I understand that interferes with my understanding on the situation).

Love you all! <3