Gizmo, Unless your playing HC. Companions are generally invincible. They can never "die" from attack, and usually they are only good at Helping kill things. Plus gave the right weapon they can do tremendous Damage. Mercy, Annabelle, Anti-materiel Rifle etc.
I've never tried it without HC. :shrug:
Bethesda/Obsidian should have done, instead of having so many speech checks, they should of added "Charisma" Checks instead, that would of called for a much needed stat. Such as talking with Red Lucy about a bigger reward should of called for a 6,7,8 charisma check.. or... the "smaller" Speech/Barter checks have like 4-5 Charisma check.
Charisma does not make you a good speaker, it makes a good speaker great.
(But in terms of these games... I'm in favor of both kinds of checks; perhaps even both checks at once to trigger an event or dialog path.)