This argument is going around in circles, because there's too much focus on special cases. Let's talk about general cases first.

I like to think of genin, chuunin and jounin like belts in martial arts.

Genin is white belt. White belts can do two or three basic punches and kicks, or so. Maybe know a really simple basic form or stance or block. Genins can use replication, which is the first ninja technique they learn.

Chuunin is like red belt. You can do Palm Heel Strikes, Elbow Strikes, 6 types of kicks, break boards, you know the basic tenets of the philosophy pretty well. Chuunins can lead, have good versatile technique toolkits and have their priorities straight (for the most part).

Jounin is like a 2nd degree black belt. You're a master of the philosophy, you're versatile in the arts in general. Does that mean you'll win every fight? Certainly not. Does that mean you'll win every fight with a white belt who's got 18 inches of height and 12 inches of reach and 200 lbs and a background in some other martial art? Not at all. Does it mean you're versatile and good in a lot of situations, and know the ins and outs of your art better than a red belt? Very likely. Not every black belt is going to be stronger than every red belt, or even exceptional white belts. Just like when I was in taekwondo for a few months and the instructor (a 2dan black belt) couldn't get basic techniques to work on me because I am just overwhelmingly big.

Gaara is certainly a special case. Naruto is definitely. Sasuke? You bet. Even Sakura is a special case, despite people's naysaying. Neji and Hinata? Lee? You better believe they aren't normal. I'd say the only "normal" cases we've seen would be tenten, ino, and chouji. They have their techniques, their techniques have flaws, they're growing but they're not stronger in any field than your average next level up.

Now let's talk about more specifics. Why can Kakashi only do Chidori 1 time more per day than Sasuke can? An easy explanation is that Chidori requires the use of Sharingan. Since Kakashi isn't an uchiha (and thus not built for sharingan) it saps his strength a lot more than a born sharingan-user like sasuke (who is probably almost at the point of sharingan being second nature now). Add this built-in drain factor to a powerful chakra-heavy technique, and realize that on top of that it's not the only tool that kakashi has or would use, and you've still got room for him to have significantly more chakra than Sasuke, just that he uses more of it doing the same things when the same things involve the use of sharingan.

I think of the Sannin to be like 4th or 5th dan black belts. Jiraiya is stronger than Orochimaru. Orochimaru is tactically smarter than Jiraiya. Tsunade, we don't know about. I'd put the third at around the same. These are people that you almost never see fight, and especially never see fight each other, but when they're serious nobody below that level can really get anywhere close to them.