Thats exactly what Dualcaster Mage is for
Split cards, by definition, can only be instants or sorceries as the rules don't want half a split card on the battlefield
Remember, Prowess triggers when you play non-creature spells, so playing more Shrines and other enchantments is going to pay off here
We want cards that make sense. While thats the starting point, he also says they dont want to spend a lot of time and energy putting gorgeous, amazing art on cards that we dont think anyone would ever want to do anything with, meaning playability is also a factor to some degree
It's especially deadly in go-wide strategies that want to close the game quickly
Lightning Greaves Arguably Magic's best equipment, Lightning Greaves serves the dual purpose of being a free haste enabler and protecting one of your important creatures