Consider this Kled can be targeted by tower and become dismounted and tower ignores after but oh wait that last shot after he gets dismounted... he ignores it just an illusion.
Because Kled dismounting makes him untargetable for a split second. If it didn't, losing Skaarl would pretty much be a death sentence for him.
He has a lot of health and shield combined and when he gets low he gets knocked off his mount strikes 3 times, between items and runes this can be a blink of an eye, hops back on with an even bigger shield than he had before which only goes away long after he has killed whoever knocked him off his mount.
Kled's "shield" outside of his ultimate (which is an actual shield) is actually his health. Kled has two health bars. One for himself, and one for Skaarl. While mounted, Skaarl takes damage for Kled and once she flees, Kled himself takes damage.
But I have my opinion what about you?
Currently Kled has a high win rate at 52%, however his pick and ban rates are low at 3.8 and 4.8% repectively. If Riot were to nerf him, which I doubt they will do as he doesn't come close to the upper limits of their new balancing framework. They will more than likely give him a love tap rather than nerf him hard. Chances are, they aren't going to touch him.