What If Nightwing lead the Arrowverse?

I've previously made a structuring of the way Arrow would've worked if the CW made a Batman TV show instead of a Green Arrow show due to the influence of Batman that was spread into the roots of the show. However, that doesn't extend to how the rest of the Arrowverse would work, so today I'm replacing Arrow with a Nightwing series that would create a television universe in the same way Arrow did (though at a smaller scale)

Nightwing
Airing: 2012-20

Seasons: 8

Plot: Nick Grayson has served as Batman's sidekick for ten years as the boy wonder, Robin. However, Nick is now 18 and after a fight with Batman over Nick's girlfriend Barbara Gordon earning the duo's identities as well as her taking on the mantle of Batgirl. As a result, Robin and Batgirl move to Bludhaven

Protagonists:


 * Dylan O'Brien as Nick Grayson/Nightwing
 * Emily Bett Rickards as Barbara Gordon/Oracle
 * David Ramsey as John Diggle
 * Caity Lotz as Helena Bertinelli/Huntress
 * Anna Diop as Raya Vestri
 * Katie Cassidy as Elise Svoboda
 * Jensen Ackles as Bruce Wayne/Batman
 * Nat Wolff as Jason Todd/Red Hood

Antagonists:


 * John Barrowman as Slade Wilson/Deathstroke (S1)
 * Manu Bennett as Mark Desmond/Blockbuster (S2)
 * The Court of Owls (S3)
 * Neal McDonogh as Damien Darhk (S4)
 * Josh Segarra as Heartless (S5)
 * Kirk Acevedo as Ricardo Diaz/The Dragon (S6)
 * Alexander Siddig as Ra's al Ghul & The League of Assassins (S7)

Harley & The Sirens
Airing: 2014-

Seasons:

Plot:

Protagonists:


 * Jane Levy as Dr. Harleen Quinzel/Harley Quinn
 * Peyton List as Dr. Pamela Isley/Poison Ivy
 * Melissa Fumero as Selina Kyle/Catwoman

Antagonists:

Joker's Law
Airing: December 2-3, 2014

Crossover: Nightwing & Harley & The Sirens

Plot: It's Christmas Eve in Gotham City and the Joker (with the help of his new assistant Punchline) breaks out of Arkham Asylum, causing the city to go into lockdown with Batman forcing Selina, Nick, Barbara, Jason, and Tim to stay locked down as well. However, figuring that one mortal man can't be that dangerous, only Selina and Tim stay in the Batcave, causing fateful reprecussions.

Protagonists:


 * Jensen Ackles as Bruce Wayne/Batman
 * Dylan O'Brien as Nick Grayson/Nightwing
 * Emily Bett Rickards as Barbara Gordon/Oracle
 * Melissa Fumero as Selina Kyle/Catwoman
 * Jane Levy as Dr. Harleen Quinzel/Harley Quinn
 * Peyton List as Dr. Pamela Isley/Poison Ivy
 * Nat Wolff as Jason Todd/Robin
 * Kevin Conroy as Jim Gordon
 * Asa Butterfield as Tim Drake
 * John Cleese as Alfred Pennyworth

Antagonists: Jared Padalecki as The Joker & Alexis Kaye/Punchline

Deaths: Nat Wolff as Jason Todd/Robin

Birds of Prey
Airing: 2015-

Seasons:

Plot:

Protagonists:

Antagonists:
 * Caity Lotz as Helena Bertinelli/Huntress
 * Dove Cameron as Stephanie Brown/Batgirl
 * Katheryn Winnick as Dinah Lance/Black Canary
 * Laura Prepon as Holly Hall/Hawk
 * Minka Kelly as Dawn Hall/Dove
 * Moon Ga-young as Cassandra Wu-San/Orphan

Heart of Hush
Airing: November 30-December 2, 2015

Crossover: Nightwing, Harley & The Sirens, & Birds of Prey

Plot:

Protagonists:

Antagonists: Dr. Thomas Elliot/Hush

Deaths:

Gotham Knights
Airing: December 1-3, 2016

Crossover: Nightwing, Harley & The Sirens, & Birds of Prey

Plot:

Protagonists:

Antagonists:

Deaths:

The New Teen Titans
Airing: 2017-

Seasons:

Plot:

Protagonists:


 * Asa Butterfield as Tim Drake/Robin
 * China Anne McClain as Koriand'r/Starfire
 * Kiernan Shipka as Rachel Roth/Raven
 * Ethan Cutkosky as Gar Logan/Beast Boy

Antagonists:


 * John Barrowman as Slade Wilson/Deathstroke
 * Joseph Morgan as Brother Sebastian Blood
 * Tony Todd as Trigon

Gotham Knights 2
Airing: December 1-4, 2017

Crossover: Nightwing, Harley & The Sirens, Birds of Prey, & The New Teen Titans

Plot:

Protagonists:

Antagonists:

Deaths:

Batwoman
Airing: 2018-

Seasons:

Plot: Thirty years after Batman mysteriously disappeared, Gotham is a city in despair, and it's under the watch of military-grade Crows Private Security, which now protects the city with omnipresent firepower and militia. When the Alice in Wonderland gang targets the firm, Batman's daughter Kate returns home, deciding that if she wants to help her family and her city, she'll have to become the one thing her father loathed her being -- a vigilante. With the help of her old friend Mary and the crafty Luke Fox, the grandson of Wayne Enterprises' tech guru Lucius Fox, Kate Wayne continues the legacy of her missing father. Armed with a passion for social justice and a flair for speaking her mind, Kate soars through the shadowed streets of Gotham as Batwoman.

Protagonists:


 * Ruby Rose as Kate Wayne/Batwoman
 * Meagan Tandy as Sophie Moore
 * Camrus Johnson as Luke Fox/Gotham Knight
 * Nicole Kang as Mary Hamilton
 * Elizabeth Anweis as Selina Kyle

Antagonists:


 * Rachel Skarsten as Beth Wayne/Alice
 * Peter Outerbridge as Roman Sionis/Black Mask
 * Nick Creegan as Marquis Jet/Joker II

Gotham Knights 3
Airing: December 2-3, 2018

Crossover: Nightwing & Batwoman

Plot:

Protagonists:

Antagonists:

Deaths:

Gotham Knights 4
Airing: December 1-5, 2019

Crossover: Nightwing, Harley & The Sirens, Birds of Prey, The New Teen Titans, & Batwoman

Plot:

Protagonists:

Antagonists:

Deaths:

Red Hood & The Outlaws
Airing: 2020-

Seasons:

Plot:

Protagonists:

Antagonists:
 * Nat Wolff as Jason Todd/Red Hood
 * Chelsea Zhang as Rose Wilson/Ravager
 * Dylan Minnette as Connor Kent/Superboy

Batman Inc.
Airing: 2021-

Seasons:

Plot:

Protagonists: Jensen Ackles as Bruce Wayne/Batman

Antagonists: