Please quote me saying most chakra=strong.
I never said that, nor will i.
My main point was that chakra capacity helps and allows more jutsus to be used.
For example most agree kakashi having more chakra would make him much more formidable etc etc.
More chakra = stronger is only slightly true when you consider the users jutsu.
If the user is pain for example, imagine him with little chakra, he wouldnt be able to use most of his jutsus at all and would wear out easily.
So while chakra amount doesnt have any direct indication to strength-it sure does help.
All my point was is that his chakra capacity is huger than any other character, and he has the skill to use it with deadly force.
While it is true kisame is only being sent after 8tails because everyone else is dead, that doesn't change the fact that kisame KNOWS tobi and it appears kisame is much more involved.
Tobi would not have ordered Kisame if he thought Kisame would get pwned entirely.
Kisame is most definitely more powerful than sasuke who lost to 8tails over and over again to be saved 3 times by his team-mates.
Kisame has way much more experience, strength and skill, and knowledge.
While it hasn't happened yet, its a dead cert that kishi is going to power up kisame soon.
For a start we havent seen him use any trump card jutsus, of which akatsuki usually have around 3-4 of (Deidara with molecular bombs, garuda C3, and his final garuda C4, sasori with himself, 3rd kazekage, and 100 puppets,pain with giant shinra tensei and the moon jutsu, itachi with tsukyomi, amaterasu,susanou, sword of totsuka and yatas mirror)
Akatsuki usually have a myriad of huge ass killing jutsus of tremendous power.
So far kisame has used taijutsu with skill, water prison jutsu which zabuza of standard jounin rank could do, and 5 small shark summons which didnt appear to hurt Gai much.
For him to be in akatsuki he must have way more power than that, we simply havent seen it.
Same can be said for zetsu, i reckon he is a badass fighter when it comes down to it