WARNING: The following article contains spoilers for Batman #109 by James Tynion IV, Jorge Jimenez, Tomeu Morey, Clayton Cowles, on sale now.
The Dark Knight has always been a solitary figure. Even those closest to him have been kept at arm's length most of the time. But lately things have started to change in Gotham City. Batman has opened his circle of trust to include more and more people, some of whom he would never have considered as allies as recently as a few years ago. He's famously been more trusting of Harley Quinn, he nearly married Catwoman, and most recently he's taken on Ghost-Maker as a new partner following his son's departure from the Bat-Family.
It's been an odd change of pace for the Caped Crusader. He's acting more like Superman than himself, to a degree. He's still Gotham's Dark Knight, but as of late he's been experiencing an evolution of sorts.
Although there are many reasons why this could be happening, one recent incident might provide the best explanation. In the aftermath of the Joker's war against Gotham, Bruce Wayne's fortune was given to Lucius Fox, meaning Batman had to be more frugal with his crimefighting. This has contributed largely to Batman's effectiveness as a crime-fighter. The resources he could tap into are now diminished, decreasing the scope of his ability to keep Gotham's criminals in check.
At this point, it makes sense that he would start to place more faith in others. Batman has always been logical, and he knows that with his current resources he just can't patrol Gotham the way he used to. But what makes him more like Superman is that he's choosing to put his trust in former criminals.
Harley Quinn, Ghost-Maker, and Clownhunter all have violent criminal pasts, yet Batman believes in them, perhaps seeing the hope in them that he's having a hard time seeing in Gotham at the moment. If people who were once monsters could pull themselves out of their own darkness, then surely it isn't so impossible to imagine the same for the entire city.
Of course, this is still Batman. Just because he's working with these people doesn't mean he has no contingencies for them. Batman became famous for his paranoia thanks to the "Tower of Babel" storyline by Mark Waid, Howard Porter, Steve Scott, and John Kalisz, where he kept files on how to defeat his fellow heroes. If he did that for literal paragons of virtue, then it's almost a sure thing that he has plans in case any of his new allies fall out of line.
That being said, right now Batman is choosing to see the best in others, which is closer to something Superman would do. He needs allies and this is largely what he has access to in Gotham at the moment. But this could also be the beginning of a positive change for him. Batman has always functioned best when there were others to balance out his darkness. Allowing more people to get close to him could help lessen the burden of the dark days ahead.