The DCAU Defenders were featured in the JL episode "The Terror Beyond":DC's "Defenders" are like ... when Denny O'Neil had Batman, Green Arrow and The Question team up, I think. Alternately I suppose the old trio of Richard Dragon, Bronze Tiger and Lady Shiva kind of fit that bill, sorta ... strictly speaking it would be more like, I mean, because then again, Marvel's comics Defenders had a bunch of incarnations of varying status ...
G1 was Strange, Namor and Hulk, yeah? So ... Doctor Fate, Aquaman and ... I mean DC doesn't have an overt "good guy" Hulk analogue but the closest thing to the Jekyll/Hyde thing is Etrigan? I'd rock out to a Fate, Arthur and Etrigan team-up. IMAGINE the Lovecraftian crap THOSE THREE would have to deal with? And the Arthurian influence! Eventually Silver Surfer drops by to help ... in our case we'd have Black Racer show up, and we'd have a fearsome foursome of Aquaman, Doctor Fate, Etrigan and The Black Racer. Nighthawk comes to hang out? That's just your inevitable Batman guest spot.
New Defenders was a bunch of real rando characters. Secret Defenders and on down the line. I thought the Netflix Defenders must've at least had some historical comic version prior to being teamed up for the crossover but apparently not? I actually have no clue who that team would be. I'd sub Nightwing for Daredevil but after that? Ah, just throw it back to the Denny "kung-fu detective trio", then add Nightwing because everything is better with Nightwing.