Gunn is well placed to take a non-traditional route and rather than waste time setting up each character just jump in with dozens already running around and worry about back story later. In media res. It’s how it works in the comics. We all encountered a universe with hundreds of people just already there and an assumption we know who they are
The Morrison run really IS a great roadmap - it establishes immediately that there’s an entire LINEAGE of Robins. Dick has “graduated”, Jason is dead (there’s a window to bring in parts of “Under the Hood”), Tim is the present day foil to Damian who is the disruptor of the status quo when the movies begin
Damian needs Dick, Jason AND Tim to work best - they all support his arc in different ways
Introduce Barbara as already disabled and training up Cassandra. Have them in Super Girl or Swamp Thing, wherever they work tonally. The Bat Fam should be all over the universe not just in Batman movies
Do Batman Inc in a TV show. Man-Of-Bats, Ranger, David Zavimbe in Africa, Jiro in Japan…these guys are a WET DREAM waiting to happen in the classic Gunn style