Let that sink in for a minute a premium, Expanded Universes product will be played in official competitive tournaments
It kills things much cheaper in both cards and mana
One good option to start with is Warriors: a creature type that has received a fair amount of support in the last year
Charix, the Raging Isle + Ragost, Deft Gastronaut Charix, the Raging Isle and especially Ragost, Deft Gastronaut are not really scary, but if you have a phobia of crabs or lobsters, you want to scroll past this
Ramp Mardu (red, white, and black) decks don't have access to any of the land ramp available when a deck includes green, so your options for mana acceleration are pretty limited
For instance, if Lorehold's effect was a loot (drawing then discarding) instead of a rummage, the combo wouldn't be nearly so clean (it would still be powerful, just a little easier for your opponents to disrupt)