I will know explain to you how the third raikage A was young when he become first and how he did it. First he was a prodigy of a shinobi or a ninja and also very distinguished one . When the gold and silver brothers did the coup . They killed anyone who could oppose them and the village was ruled by fear .
They thought but the did not expect a person like third raikage at a young age they not expect what probably a who was preteen or early teenager to be a threat to there power dispite how talented he was after there greatest triumph the killing of the second hokage tobirama is wear the third raikage made his move there force was weakened along with the gold and silver brothers it was the same mistake that king Richard II made because they ruled by fear and not any support or consent and once people like that leave the country what do the oppress have to fear .
So that is when the future third made his move and also he made a lot concessions including a huge kumo council you don,t have a council that big unless you are going to share power with them he weakened the raikage position into something of CIC executive position .
They did this for a few reasons 1 to prevent a gold and silver brothers uprising from happening again. 2 the guy who got himself name the third raikage was in his minority and was while mature for his age both physically and mentally was still but a kid and putting that must stress on him was unhealthy and detrimental. 3. To prevent future village leaders from becoming a tyrants. 4. Reason mention above limiting the power of village leaders and preventing them from becoming tyrants.
The third manage to rally the people and get himself made raikage . He also manage to get the gold and silver brothers captured alive after there greatest triumph which where added to the Landry load of chargers. When they where put on trail wear they where sentenced to death on multiple fronts including multiple of Grievous counts of murder. High Treason against the village and county. The coup on the second raikage and the murder of them .Also because the third raikage wanted to end the first great ninja war along with a lot of people they where also convinced of murdering the second hokage tobirama senju they where found guilty of all charges including ones not listed above. There death sentence was carried quickly.