I haven't figured out a team. I haven't been playing for two years, either.
Have quickly come to a realisation that an EX character or Karate is almost compulsory for a good team. But I don't like using any of them.
They're far from necessary. Consider what's needed for a team to be good:
1. Able to do good without a lot of meter. Good meterless damage output, strong neutral game tools are things to look for. Ability to build meter.
2. Able to utilize meter for extra tools or able to do lots of damage with small amounts of meter. Ability to build meter for the third character to use. The 2nd slot is the most freeform one, and almost any character can do well in it.
3. The key here is ability to convert all the amassed meter into tons and then tons of damage. Oppressive neutral game tools to do reverse one-character wins can be a consideration.
The important thing in building a team is that you have all the tasks covered. No one character
needs to do everything, though it's useful.
The DLC trio are great and have the advantage of being at home in any slot (though EX Kyo probably isn't the best choice for anchor) because they're so good all around. They have a solid neutral game and scale well to any amount of available meter. But the DLC trio aren't the only universal top tiers. Benimaru, Kim and Hwa Jai fit the template to a T as well.
In addition to that, though, there are characters that strongly prefer certain slots due to their ability to use meter, or their need of meter to do things. Duo Lon and King, for example, completely suck as anchors due to their poor ability to convert meter into insane damage. But used as a first or second character where that ability isn't relevant or is less relevant, they're a match for any top tier. They have good meterless damage, nice buttons, good space control... anything one of those universal top tiers have. And since the meter amounts are low, their weakness doesn't really ever become an issue.
Likewise, there's characters like Claw Iori and Vice that can do ridiculous amounts of damage with meter. They also have OK neutral games, but need meter to get access to the EX moves and supers that patch some holes their meterless neutral game has. As such, they tend to need meter to be truly scary, which means putting either one on point is a bit questionable. But as an anchor, with a lot of meter available, they're only the tiniest bit behind the top tier, if they're behind at all. They also tend to do OK in the middle slot because they have some meter available.
So, you can build teams like EX Iori, EX Kyo, Karate or EX Iori, Karate, Kim. Sure. Rock solid, neither team really cares about character order so you can game matchups all you want.
But something like, say, Duo Lon, Kyo, Claw Iori is just as solid as that team. It just cares about it's order a little more. And even then, while all three prefer the slots I assigned them, Kyo is OK 1st or 3rd, and neither Duo Lon nor Iori terribly mind being 2nd, so you can still switch around a bit.
Or you could run Duo Lon, King, Vice. Again, rock solid, but a step more rigid because Vice really can't leave the third slot. You still have absolutely solid characters in every slot and can switch Duo Lon and King around.
Or see Juice's team: King, Takuma, Leona. Again, a bit order constrained to be sure, but against the field in general you can't really find fault in it. Leona's a good anchor, King is absolutely stellar on point, and Takuma can do monstrous things with only a little bit of meter.
There's a lot of really solid teams you can build if you put your mind to it.