I didn't mention Barbs and DKs because they aren't really like charmer's 7 yard stun, and you mentioned why and how they can be countered.
You can't kite out the Charmer like DK, because he can just cycle the 4 skills again and again. Then there is this little chance that this hit gets blocked (not everyone can) or dodged (accuracy solves it). Charge also has chance to fail AND chance to miss with dodge/parry/block, so we're fine on that.
It also increases the damage a lot, so not even the best shield (unless maybe maxed up, which isn't really a PvP build) will make it deal 0.
Now the funny part about Paladins..
It is very rare to get advantage of that 6th yard unless you're talking about 1v1. In Arena you don't wanna sacrifice the whole radius to catch the farthest dude, normally, you wanna catch as many as possible, and that can lead to stunning in range of 4 to 5, or even 3 yards > easily outranged. And if you don't catch all, then you're getting controlled and eventually killed, so add to that the high risk, like Barb's Charge.
And it's funny how you kinda contradict yourself mentioning 4 classes that can stun the Paladin before jumping, and then wonder why is no one talking about Paladin being OP for the 5-6 yard AoE stun. And if it comes to being 5 yards, then you can add almost every class can stun before the Paladin jumps.
Also Call can easily fail due to screen bug even if the opponents didn't give any effort to separate and avoid getting stunned in that small 3x3 radius. You talked about that kind of people that complain about stuff that may look OP but you can easily figure out. You're not one of those who stand on top of each other in a 3x3 radius in Arena, right?
So let's and stay in the topic and not act like perfect community-healthy players and all-knowing and belittle everyone who oppose us.