You've ever played with a bunch of figurines and such at once? Build a group, or an entire army of them and face them against threats as big as you could possibly imagine at the moment? Your imagination was the only limit, since there was no franchise or creative boundaries. Superman could fight along Spider-Man, Harry Potter could face Captain Planet, or Batman could ride your mom's dildo. As I said, your imagination was the only limit.
I see the same in this comic - there's pretty much everything that Scott Snyder could possibly come up with, squeezed and crammed together no matter if it makes any sense or not, with anything possible at any given time. And the same way a child can come up with impromptu deus ex machina solutions to equally impromptu deus ex machina problems, Snyder leads a chaotic narrative where nothing and no one ultimately matters, because it all can be changed, fixer or undone by anything or anyone else. Oh, look, Batman lost his hand, of course off-page, and his Black Ring won't work anymore, imagine the shock, he's going to die for good! But wait... of course he didn't put it on his finger, what a twist, he stands up and resurrects everybody who died on the battlefield, and then Sailor Moon and Skeletor joined the fight and... and... Godzilla told an army of Hot Wheels to give her a lift to the nearest Micky Dee's because dad brought some Big Macs for us.
Yeah, seriously, this entire event seems like something where end justified the means even more so than in Doomsday Clock (which I actually truly enjoyed, but I get why so many readers have some serious gripes with it). Anything and everything to introduce the idea of the Omniverse. Creationists would be proud. I am not. I feel like Death Metal started out pretty damn good just to quickly derail and lose any illusion of plot it may have had initially, so DC can try to address the pisspoor reception of some things they've introduced in recent years that infuriated practically everybody.