Synergy with the rest of the clan can be just as important in that case. But it is generally necessary to win a good number of matches with a majority 2-star draw if you're gonna have four of them in a deck.
That means either picking serious nukes as your other cards (risky), or concentrating on 2's that can kill.
Bangers, though they do have reliable 2-stars, will not kill you. Won't even come close, really, and one nuke probably won't make the difference.
Freaks, with their effective two-stars + Poison, can most definitely kill, and a perceived necessity to hit on the first hand can lead to a lot of bluff opportunities.
Skeelz can completely shut their opponents down, depending on the hand. Getting that damage through is a pain, though.
GHEIST can most definitely kill you on pure damage, backed up by their tricky bonus. Attack manipulation hurts bad, however.
Sentinels can easily take on an equivalently-starred hand, but may run into trouble in the damage department if they get too much opposition. Same with Piranas and All-stars.
Personally, I would choose either Freaks or GHEIST. I must admit, however, that I don't have a terrible amount of experience with some of the other clans.
Jungo - Mindy, Pegh, Wendy, Somba
3, 3, 4/6, 5 life gaps (if you incl the bonus). with dr and +attack and good power.
Butch, CWing, Cyb Lhia, Neloe
solid power, dr, poison, and a good bonus
I also like honorguard's nm suggestion above.
Freaks - Harleen, Esmeralda, Hula, Magda;
Junkz - Gil, Dreen, Veenyle, Sentogan;
Bangers - Massiv, Graff, B Ball, Bennie;
Rescue - Lea, Steve, Krash, Larry, Vinny, Lothar;
Nightmare - Phyllis, Eadh, Mawpin, Sheitane;
Sakrohm - Wakai, Nimestiec, Embolt, Na Boh;
Pussycats - Wanda, Brittany, Feelyn, Ella;
Vortex - C Wing, Cyb Lhia, Neloe, Butch.
HonorGuard is exaggerating the effectiveness of that Nightmare lineup quite a bit.
Think about it practically, those stats he's given are way off.
Sheitane has to hit first to be that effective. The Freaks are just as effective if you hit the opponent at least once more.
Phyllis can't kill you. Either her or Sheitane have to be played first to be effective, and are thus are somewhat predictable.
Mawpin is predictable as well. If your plans don't go quite so well, his ability is easily avoided.
Eadh is the only solid member of the group, with three damage to his name.
This team will get you around other two-stars who rely on their bonus, but they lose a certain advantage if playing first. This is a team which definitely has to be mixed in with some nukes.
They have 2 great ill just list the 4 best 2 stars in eacg clan (my opinion and u can decide 4 urself)and ill rate them
All Stars- Jessie stacy Miss Jessie Ashley ( 2 great 2 not so great so if ur looking 4 4 its not here)
Bangers- Graff B Ball massive and kevlar (great 2 stars one of the ones id recomend)
Fang Pi Clang- Chan Marlysa Cr Yumi Unagi (good ones but the cr is about 700000)
Freaks- (Esmerelda Hula Harleen Magda) (ok but i wouldnt recomend them)
GHEIST- Zero dead akrin Platinum lumilla (not really worth it)
Jungo- Wendy Pegh Mindy Borss (nope just a liitle 2 weak on the stats)
Junkz- gil weenyle Dreen sentagen (probly above average sentagon is lacing but still a decent card so this is a good choice)
junta- Dreen Wardog thourmand 2 star jane ramba/Winston (i believe these r good but u might want a bonus that helps ur cards win considering they r ur weakest cards.
Montana- spiaghi Prince Jr filoma fransisco (all ok/ good cards but they just have really bad base stats)
Nightmare- Phylis mawapin Eadh shetline ( all good shetline is old though i think they r towards the top of the list)
Piranas- Hawkins Tula Hawkins Noel Spycee (Hawkins and Tula r great noel is ok Spycee is dreadful in my opinion wouldnt recomend it)
Pussycats- Britney 2 star Gwen effle feeyline (i dont like them)
Rescue - Lea Steve Krash Larry (all ok but dont go there unless ur usin mono)
Roots Arno Jeena 2 star micken moose Jeto ( if ur lookin 4 defense its good but u wont win much with
Sacromh nimestec Na Boh Embolt Wakai (nimestec and Wakai r ok the other 2 r card i personally hate)
sentinal Lehane Tobbie Kyle Rick ( actually not 2 bad though not as good as the Nightmare and Junkz its definently a viable option)
Skeelz Sasha Redra wilheem Anton (nope maybe Liam should be in there but idk dont do it Skeelz are known 4 their 3 stars)
ulu wtu- Bree gabriele Taigo Jeff-(nope dont like them either)
Uppers- wendal Samantha collin micky t (oh god please dont even think about it 2 3 powers a 5 power and a 6 power just not 2 my licking)
Vortex- Cyb Lhia C Wing Butch neole ( recomended for a range of uses)
so my recomendations in order r....
1. Nightmare- Mawapin Eadh phylis shetline
2. Vortex-Cyb Lhia C Wing Butch neole
3.Junkz- gil veenyle Dreen sentogon
4 sentinal- Lehane Tobbie Kyle Rick
5.La Junta- Dean Wardog thourmand 2 star jane ramba/Winston
I played a Sentinal / Ulu deck with 4 2* in it, and it's a winnable draw:
Lehane, Tobbie, Aurelia (who should now be replaced by new blood) and Taigo.
All of them have huge power plus attack manipulation, and I've won all 4 rounds with them before.
Your milage may vary though, especially depending on which clan you face.