chronological mistake? or kishi hadnt thought of his storyline at that time

[Chie]

check the Manga when Iruka asked Kakashi not to nominate Naruto for Chuunin he said to Iruka "he was Six Years when he became Chuunin".

Yes. Iruka stated that back in part one when he was discussing whether or not Team 7 should participate in them.

That has nothing to do with Kakashi being a Jounin at age 12. Nothing with Kakashi's advancements was shown to be a mistake.

You said he was shown to be 12 and a Chuunin. The only time we see 12 year old Kakashi is in the Kakashi Gaiden arc that was shown upon the conclusion of part one. He was already a Chuunin (since age 6) and promoted to a Jounin on his 12th birthday. There's nothing wrong with this.

 

[Lightbringer]

No, it's not.

Some time passed between the latter two panels. He heard Tobirama's remarks. He became convinced even more so that Tobirama had his bias towards the Uchiha (which he did) and reflected on this. It caused him to have a negative outlook and he didn't believe Hashirama would help the Uchiha clan politically if Tobirama was around. The panel with Ohnoki evidently occurred during the time he was reflecting (so between Tobirama's remark and Madara's own defection from Konoha).

I think this is a good explanation

 

[Tsukikami Uchiha]

it happened between the two incidents, he overheard the convo then went on to try and convince his fellow clansmen to join him, and while he was at it he may have been sent to do the peace treaty thing and decided to vent on the two fodder cos he was pssed and frustrated that all the Uchiha he approached at the time would rather stay with Hashirama than him despite he being their leader and the fact that it was for their good that they followed him. Then after the fight he spent some more time pondering and trying to gather more Uchiha until he got fed up, called Hashi to the Uchiha Nakano shrine and deflected.. warning him that he'd return as the solo god and solo the entire world and all bijuu neg diff.

that is the chronicle of the SoloGod Madara Uchiha