Possible Clues:

• In favour of organising riot in first class? That's the most convincing conclusion!
• Agricultural leader behind atrocious riot on island? That's the most convincing conclusion!
• Even more certain, in logic
• Strategic position - one soldiers held in capital more conclusively
• Latin phrase: With even stronger reason than that already accepted
• For a stronger reason it's strong, or among eleven more
• More conclusively, what makes stick or sick sack?
• A defensive place, one with gold, one with more convincing reason
• Keep one first, one with gold, one with greater reason
• In compiling, Afrit (without love) or Enigmatist (with stronger reason)