The only other one-drop in Pauper that can trade with Delver on defense is Oonas Gatewarden, and that one does not have the advantage of being able to attack
He offers so many lines of play each turn that he functions as a one-card control engine
Also, when Grimgrin attacks, you get to destroy a Creature the defending player controls, and then put a +1/+1 counter on it
Stormfront predates the published-odds era, so there is no official Pokemon pull-rate sheet for it the way there is for modern sets
Combining haste with beefy threats like any of the Ghaltas featured herein or something like Zacama, Zetalpa or Apex Altisaur is a huge play, so its no surprise to see this Dino lord so high up
Great when behind but also a proactive threat if needed