In other words, the last thing on earth we would want to do is create that scenario for ourselves with FlingFling effects
Seriously, nearly every card thats ever broken the game has been related to cheating mana or something similar
Raph & Leo, Sibling Rivals Raph & Leo, Sibling Rivals have one of the easiest extra combat effects in the game, and untapping two attackers has a multitude of uses to make this exceptionally good for an easy to cast three hybrid mana
White's recent design philosophy feels like it's been "you can do this, but", and Late to Dinner is a really nice break from that
With the extra benefit of persist, Glen Elendra Archmage can come back to take care of another noncreature spell or be a chump blocker
Set Boosters also drop an art card, and in Dominaria United Set Boosters, signed art cards appear twice as often as in previous standard-legal Set Boosters