Ultimately, it's better to have a team made up of the better characters and not to worry about forming certain teams. I personally like to try and have a character for each of the three main archetypes, so that I can switch out to take advantage of any type weakness at any time, but the changes coming to Universal characters might make them more effective team anchors here soon.
Spider-Man is one of the better Speed heroes in the game, and probably the best in terms of ease to get bios for (I think people generally find Gamora more effective, once she's ranked up, but her bios aren't easily grindable); he dodges shit like it's his job, he's got great crowd control, a long and effective stun, and great damage- plus he's one of the handful of characters with a 6* skill, increasing his usefulness in endgame content.
I like Daredevil quite a bit, and find him fun to play- he's got a decent stun, and I like the feeling of linking his skills together. He's heavily overshadowed by other characters in his class, and so he lags behind a lot. That said, it sounds like the update is going to hook him up with a new costume, which could radically increase his effectiveness. Punisher isn't great, in my experience anyway, and it seems like he needs his (now unavailable) uniform to really compete.
Of those characters in your reserve right now, Groot is a fantastic character as he gets higher tiered. At 3 stars, he'll get a healing ability that does wonders in more difficult fights and turns him into a great tank, and since he's a Special Mission character, he's one of the easiest in the roster to grind. Gamora is great, but as I mentioned, getting her ranked up at this point is either going to be a long grind, or a bit of a money sink. Angela seems solid, but I haven't used her too much- the universal type buffs might radically change things for her. The only character you're currently tinkering with that I really didn't care for was Blade- his skills always felt janky and underpowered to me, and I couldn't get much out of him when I tried to build him into a decent Villain Siege tool.
On the note of tanky characters, you may want to look into investing in Giant Man; the Pym Hand is too strong in this game- him and Yellowjacket are overpowered to the point of easily steamrolling most of the content if you grind for them, their bios drop pretty frequently, even compared to other Special Missions, and as a result they're some of the easiest to grind in the game. Hank is an absolute monster in both the numbers he dishes out, and how much he can absorb, and the top tier teams are usually comprised of both Pym and Yellowjacket.
I should also stress that there are people in this thread way more qualified to talk about the math and effectiveness than I in this thread- since I don't even have any 6* characters yet, and thus don't really have a grip on what a lot of these potential very endgame potentials look like; just thought I'd give my two cents based on how I've felt up to this point.
