Your characters and items will do the heavy lifting, but without actions to support them, you could find yourself facing insurmountable odds, have no cards in your hand, or even be without a decent board state to speak of
High Alert on a stick with the most important defender colors for EDH would already make Arcades, the Strategist a fantastic pick for a commander
It also has an activated ability to draw a card and then discard a card, but that isn't the important bit of the card
Firion, Wild Rose Warrior FIN has some awesome equipment commanders, and Firion, Wild Rose Warrior is one of my favorite due to its unique ability
It's important to understand what kind of game your opponent is playing and counter their strategy with your own tools
Just watch out for the downside of your opponents resolving all of their spells, too