The artifact decks were often the best at this, because they brought out their mana so fast that they could shrug off losing two lands while they crippled their opponent's development, and decks with green mana creatures like Birds of Paradise often used the same plan
While it wont stick around forever, youve probably gotten the value you need from it by the time it leaves
And only one copy of any card is allowed except basic lands in a Commander deck
Not only that, but it reads, At the beginning of your end step, gain control of target nonland permanent controlled by a player who was dealt combat damage by three or more Pirates this turn. It can be tricky to get that many hits in, but if youre playing with cards that make your creatures tricky to block, then you should be able to keep adding more things to your collection
Edric, Spymaster of Trest One of the best card-draw commanders in Magic, Edric, Spymaster of Trest offers a very good incentive to attack more often