I believe that, in the right metagame, this deck can be a very strong choice, and the right metagame is one full of Temur deckswhich is the one we're in right now.
Green-Blue Pummeler shares a lot of cards with Temur Energy, but it plays out very differently. In fact, one of the advantages of the deck is that it can disguise itself as Temur Energy for a while, since the early plays are very similar, and then catch the opponent off-guard with a Blossoming Defense, Dive Down, or Larger Than Life that they weren't expecting. Depending on how Game 1 goes, they might even assume you're playing Temur for Game 2, and will sideboard against the wrong deck.
Your key card is Electrostatic Pummeler, which can often win the game on its own in one attack. Since the card is so strong with the right setupif you have Larger Than Life, you only need six energy to have a 20/20 tramplerthe Electrostatic Pummeler kill can bail you out of any bad situation. No matter what has happened in the game up to that point, you're always live to draw a Pummeler and attack for 40. It turns the game into a "Do you have a removal spell or not?" subgame, and, if they don't, you win, regardless of what else your opponent has in play. You can be in a spot where you're at 1 life with just Pummeler and your opponent is at 17 with three creatures out, and then you can still win that very same turn.
If you draw Electrostatic Pummeler and it lives, then you're probably going to win the game, but that doesn't mean you need it every time. Between Greenbelt Rampagers, Servant of the Conduits, Longtusk Cubs, Rogue Refiners, and Bristling Hydras, you're very well equipped to play the fair game, and your "combo pieces" actually complement this plan very well. A start of Longtusk Cub plus Cartouche of Knowledge, for example, can be very powerful, especially if backed up by a protection spell.
The deck has a lot of creature enhancements and not that many creatures, so it can often struggle against removal-heavy decks, because they kill everything you have and leave the pump spells stranded in your hand. Bristling Hydra does a fantastic job of combatting that, and it's the premier target for Cartouche of Knowledge when Electrostatic Pummeler is not in play. The way most decks handle Bristling Hydra is to chump block it over and over, and this deck makes that plan much harder to execute, since it can consistently give it flying or trample.
As it is, I think this deck is a slight favorite against other energy variants (Temur, Four-Color, Sultai), slightly unfavored versus control decks (though sideboarding helps a lot here), and unfavored versus Ramunap Red. The sideboard tries to shore up that weakness by splashing black for Cartouche of Ambition, but I don't think this is the best approach; it's a card you sometimes can't cast, and it gets blanked by Rampaging Ferocidon. The biggest upgrade to this deck can largely be done in the sideboard, to combat this particular matchup.
Fill the board with cheap 4-toughness creatures. Red decks have real trouble with x/4s, since all the cheap removal deals 2 or 3 damage, and you can easily overpower your opponent if you have multiples (Greenbelt Rampager)Rhonas's Last Stand makes a 5/4 for only two mana, but you often lose your next turn in the process; to remedy that, Sam plays Prey Upon, which can deal with Rampaging Ferocidon, Harsh Mentor, Ahn-Crop Crasher, or Kari Zev, Skyship Raider, and can always be cast the turn after you play Rhonas's Last Stand (assuming you play your land for the turn). I think this is a better plan than Cartouches, because it addresses the things Green-Blue Pummeler is actually bad against.
