While I think ToxicAdam is basically on the mark, and that the developers seem set on convincing players that they're jerks and resent players who have fun without paying out the nose, I don't find that it's very hard to place well in these tournaments with a 2* team.
My go-to for the Ares tournament was 50/85/85 Ares/Wolverine/OBW, although I also spent a lot of time with 50/70/85 Ares/Hood/OBW. And I placed top 5 pretty easily in both rounds. I don't see that this new tournament will be very different, although I completed my Punisher the other day so I don't care much about placement anyway.
FWIW, and I'm not sure which things I'm doing are actually helpful and which things are wastes of time, I enter these tournaments pretty early and spend the first 36 hours or so repeatedly building up to 100-200 points and then putting in a tank team for 12 hours (it takes 4 wins to do this and you can eat upwards of 20 losses before you have to top up). After that I build to 300-400 points and sit (to make sure nobody sees my tank team when I make my big push). With maybe 5 hours left in the tournament I get as high as I care to over about two hours. In the Ares tournament I was finding a bunch of people worth 50 points a pop who had tank teams in (I assume they were shielded), and even as I closed in on ~1800 points I was only having to fight teams of 50/50/50 Ares/Wolverine/Thor, and I was still getting 40+ points per fight. Then I shield out the last three hours, although this might not be worth the HP anymore.