This sermon has got nothing to do with people involved in the assassination of 'Uthman.
Following sermon (which brother Hani posted in the first post of this thread) is related to people involved in the assassination of 'Uthman.
Sermon 168:
When a group of `Ali's companions requested that he punishes those who assaulted `Uthman. He answered: O brothers, I am not ignorant of what you say. However, how can I accomplish this when those who assaulted are in the height of their power? They are dominant over us not we over them. They are now in the position that even your slaves have risen with them and Bedouin Arabs too have joined them. They are now among you and are harming you as they like. Do you see any way to be able to do what you aim at!?
From this sermon it seems like those who assaulted 'Uthman were known to Imam Ali (a.s) and those Companions of Prophet (s.a.w.w) who requested Qisas of 'Uthman from Imam Ali (a.s) (those Companions referred in this sermon) and they (assaulters) were not unknown/obscure.
This supports what I said. Also supports the sermon where Ali said they are obscure.
If they aren’t obscure then why is Ali (may Allah be pleased with him) not mentioning them by name rather than as ‘they’? Why is he alluding to them as infiltrators who have infiltrated the ranks of the people without the people knowing?
Clearly there was an uprising & mutiny against Uthman (may Allah be pleased with him), by tribes who had their particular grievances & concerns but also infiltration of sinister people at work (most muslims accuse the likes of Abdullah ibn Saba & his likes).
No one is saying all was hunky dorey with the 3rd caliphs policies.
Some tribes were genuinely grieved at his policy to have family members being the ruling class, some wanted land that wasn’t given, some were mercenaries who only joined Islam for the spoils of war, others were instigators of fitna like Abdullah ibn Saba etc.
The sermons support what I am saying, not you.