I'm just thinking of Zelda in how she needed to be a strong monarch for the people of Hyrule but still would need the aid of Hyrule's greatest warrior/hero. Since there's talk of a LoZ movie, I can see these same talking points for her on both sides of the aisle, and yet fans are super absolutely sure that Peach herself can't be a good monarch to her people because she has to be a ditzy blonde always getting kidnapped by an evil ruler wanting her Star Power and her hand in marriage. Boy, that sure doesn't explain why the Toads adore her.
Mario's still going to be the hero at the end of the day (probably will share the glory with Luigi), Peach will not land the final blow herself. I see nothing wrong with her giving aid if needs be, especially since Fire Peach has long been a thing, so she technically can fight off foes if she needs to.