Hey,
Welcome to the forums!!
I think that either option would be good, but I'd lean towards the second one. I'd have paragraphs on different aspects of political life and then back it up with either archeological/written evidence (make sure to include evidence for both Pompeii and Herculaneum if the question asks for both).
For example, I might talk about the Duumviri and could include a definition and this evidence to back it up:
- Inscription: ‘A Marcus Holconius Rufus, military leader elected by the people, duumvir five times ....’
- “[The duumviri] stood at the summit of the political life”-Lazer
Keep in mind the short answers don't have to be too long (heaps of paragraphs). If they are 6-8 marks they are only about a page and 10-12 marks are 2 pages. If the question includes sources, make sure to include them in your answer.
Hope this helps! Feel free to ask any other questions!