The funny thing about seeing all of Netflix's Defenders fighting together is that when you think about it, they all kinda have a variation of the same archetypical superpower. The Defenders aren't just the Marvel Cinematic Universe's street-level heroes, they all punch things really hard — and that's part of what makes them so unique.
When Netflix and Marvel first announced their plans to buff out the larger MCU with new series of shows all set in New York City, it made sense that the characters they chose to highlight would have relatively modest powers compared to their big-screen cousins. In Marvel's comics, heroes like Doctor Strange, the Silver Surfer, Valkyrie, and the Hulk have all been counted among the Defenders' ranks at one time or another, but between those characters' current obligations elsewhere in Marvel's films and obvious budget constraints, it would have been nearly impossible to bring them to the small screen.
How convenient, then, that Marvel and Netflix's modern TV version of the team consists of a bunch of relatively normal people who all just so happen to be very good at punching people. Although their powers work in somewhat different ways, at the end of the day Jessica, Luke, Danny, and Matt are going to spend the Defenders TV series taking on the Hand with their fists.
This might not immediately seem like a big deal — who better to fight undead ninjas than a group of fighters? — but there's things to be said for the ways in which we use the variance of superheroes' power sets to define a team's dynamics, and how The Defenders ignores that rule completely.
Daredevil may be decked out in full body armour and have heightened senses and years of proper training, but one well-placed punch or kick from Jessica would quite literally send him flying due to her enormous strength. Jessica may be strong enough to pin Luke's arms down while they're getting busy, but actually trying to hit his super-dense skin with her bare hands would likely end with her doing more damage to herself than him. We know that Danny's fully charged iron fist is capable of hurting Luke, but Luke can take a punch and Danny can only use the iron fist once every couple of hours.
Despite having variations of the same type of powers, the Defenders are balanced among one another in a way that emphasises how the thing that really sets them apart from one another are their personalities. Individually, Netflix's Marvel series have all done a solid job of placing their titular characters at the center of their stories in a way that's made each of their journeys, drives, and natures feel distinct from one another — perhaps to a fault. Unlike a lot of other motley super-crews whose members may briefly bristle at the idea of working together, it's legitimately kind of difficult to image Jessica, Luke, Matt, and Danny as team, let alone a group of friends.
Whereas the Suicide Squad and the Avengers have something of an obligation to do their hero work, the Defenders are just a handful of unusually strong people with virtually nothing in common. Even in the best of circumstances, none of them would get along too well, and even though they're teaming up for Defenders, there's no question that each of them considers themselves more of a loner. Unlike other superhero teams that have at least one person the others look to as the "leader" of the group, The Defenders subverts that trope by putting its heroes on a relatively level playing field (physically) and revels into the fact that they're a group of Type-As.
In the first Avengers, there's a scene where Bruce Banner insists that he and the other heroes aren't a team, but rather a time bomb — a powerful statement of their instability, but not exactly one that's borne out well on-screen. The Defenders, by comparison, aren't a time bomb as much as a collection of mismatched parts, jury-rigged together in spite of the fact that they're incompatible. It's in the inherent flawed-ness of their relationships that allows us to see who they are as people, and that's what makes them compelling to watch.
As we get deeper into shared cinematic universes with crossovers like Infinity War, it's going to become increasingly important for superhero movies to remember that on-screen spectacle can ultimately fall flat if there isn't a beating human heart at the story's center. Defenders seems to be built around that understanding, and the series will likely be immeasurably stronger for it.