in some games he becomes the leader of a victorious charge, while in others, he dies near the beginning of play or serves more of a support role
There are lots of cards that give you mana in increments of three, and most lifelink creatures worth playing already have three power or more
Voidwalker is graveyard hate while Agent is card draw, and both let you steal something from your opponent
If Krenko isnt the commander, it might still be useful in the 99 of any goblin deck
Ragavan, Nimble Pilferer (/500): From March of the Machine, this is one of the best one-mana creatures
It has trample, haste, and "At the beginning of the end step, sacrifice this token." Enchantment Tymna the Weaver Lifelink At the beginning of each of your postcombat main phases, you may pay X life, where X is the number of opponents that were dealt combat damage this turn