Its cheap cost makes it powerful, but its sorcery speed leaves the tutored card vulnerable to mill or shuffle effects before you have an opportunity to draw it
If the result is greater than the damage dealt or the result is 12, double the number of +1/+1 counters on that creature
The most popular of these commanders is Goreclaw, who itself can fulfill the Ferocious requirement, while also making all of your power 4 or greater creatures better attackers, while also making them easier to cast
Top that off with an exceptionally strong attack trigger, to put a +1/+1 counter on each of your Vampire creatures when he attacks, you have yourself a constantly growing army to take down any opponent
Sure, you sometimes help your other opponents, but it should draw a lot of focus off your creatures and benefit you as well
You can have a situation where a 2/2 token crews a 4/4 vehicle with crew 2