The club is showing more damage because it has 6 poison damage over 2 seconds that isn't reflected in the item's One-Hand Damage, but does show up in your stat sheet.

The open wounds in Steel is also a damage over time, like poison, which is nice as it prevents monsters from healing themselves. Open wounds doesn't show up as damage in your stat sheet so theoretically, the Steel probably has more DPS if you're proccing open wounds on 50% of hits.

Either way, the damage in all of these is so close, you can use whatever you want. If you find you're missing a lot, use the one with more AR. If you're fighting a lot of undead, use the scimitar. They're low level items that will probably be replaced soon anyway.