The mana production gives it a distinct Big Red strategy, as Neheb gives you the requisite mana for spells like Portal to Phyrexia and Sunbird's Invocation, with all the card filtration needed to find such impactful spells
It gives your Leader +1,000 Power that sticks during the turn, which makes it easier for you to Counter the other upcoming attacks
Ultimate Magic: Holy has further utility by preventing damage, which adds up to a total blowout
Rowan, Scion of War, on the other hand, returned from her studies at Strixhaven (Rowan, Scholar of Sparks) in search of enough magical power to set Eldraine back to the way she wants
You cant really throw Doomsday into just any deck and expect it to work, but you can build entire decks around it and win with a strategically stacked Doomsday pile