If you have evidence, such as his cigarettes from your grave, his lighter and a note from the great khans, swank will give you weapons and help you ambush benny without finding yes man. I think you can also pass speech checks instead of having the evidence.
Full mods list
https://docs.google.com/spreadsheets/d/1yDih3m2ncDTYt0IXvEjGibhPZwYfPH9MMtlCQQHIGng/edit?usp=sharing
Mods used:
NCR Ultimate Overhaul - Public Mod
http://www.gunetwork.org/t10746-fnvrelease-ncr-ultimate-overhaul-v1-0-1
47 ENB 2: The Sequel
http://www.gunetwork.org/t2762-fnvrelease-47-enb-2-the-sequel
NMC Texture pack for New vegas
http://www.nexusmods.com/newvegas/mods/43135/?
Interior Lighting Overhaul
http://www.nexusmods.com/newvegas/mods/35794/?
Fallout Character Overhaul
http://www.nexusmods.com/newvegas/mods/54460/?
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