In a meta that is as wide open as yours I would deffinitly recommend some kind of anti hate, because with BUG Landstill and Aggro Loam you have two potentional candidates for Leyline of the Void and if you got another Dredge player in your meta, then I will ensure you that the other players will squeeze more hate into their boards.
So the decks in your meta can basicly play any kind of hate, from Bojuka Bog over Relic of Leyline of the Void to Relic of Progenitus or Tormnonds Crypt.
Luckily we can handle them with only 2 cards: Ancient Grudge and Natures Claim.
So lets start with 4 of them each
->
4 Ancient Grudnge
4 Natures Claim
7 Slots remaining
The next 4 slots could contain either a playset of Firestorm, Leyline of the Void or Leyline of Sactity. While Firestorm can deal with Merfolk, Affinity and Faeries, Leyline of the Void just wins the mirror if your opponent is unprepared and Leyline of Sactity could potentional buy you the one turn you need to win against TES ( and don't get me wrong: they don't really have any problem to deal with a Leyline, but if it slows them down for one turn, then it got the job done). Also you can also shut down Crypt, Bok, etc. with the Leyline (actually the only way to deal with Bok).
As you got only 1 storm player I would recommend 4 Firestorms, because frying fish and faeries is never a bad idea.
->
4 Ancient Grudge
4 Natures Claim
4 Firestorm
3 Slots remaining
The last 3 slots should be devoted to DR targets. As there are so many different targets to choose from you should pick some targets who turn the board state into your favor.
Elesh Norn, Iona and Flame Kin Zealot would come into my mind, as each of them can win a game on his own.
Norn is great in the mirror, against Fish, Faeries, Zoo or Affinity, while Iona and Zealot are good against Combo and Control.
The final board would look like this:
4 Ancient Grudge
4 Natures Claim
4 Firestorm
1 Elesh Norn
1 Iona
1 Flamekin Zealot
The only way to find out if the board works for you is testing ;).
Well if I'm posting a comment anyway, then I can also include a short report:
Local Tourney, 13 player:
Round 1: Affinity
G1.: He wins the die roll and starts with Darksteel Citadell and some dudes, while I start with a Putrid Imp, followed up by a turn two Breakthrough. On his second turn he played a Ancient Tomb and said something about a missplay on his side, well one Therapy later he loses two Masters of Etherium and the combined force of Ichorid and Zombies take him down quickly.
G2: He leads with a turn 1 Relic, while I start with City and Study, finding a Tireless Tribe while discarding a Troll and a Grudge. On his second turn he plays a Cranial Plating, leaving one mana open for his Relic.
As the Troll is my only dredger I dredge once, play another city and my Tribe. At the end of his third turn I flashback the Grundge to destroy his Relic, leaving me with an empty graveyrd. However in my upkeep I discard the Troll again, play a Colluseum, crack it and animated a big fat Troll to seal the deal (alongside his Zombie buddys).
Round 2: GW Maverick
G1: I start with Carefull Study, discarding Imp and Thug, while he leads with Canopy into Zenith for Dryad Arbor. On my turn I cast another Study and a Breakthrough, leading to a quick surrender from my opponent.
G2: He starts with Forest and Noble Hierach and I just discard a Grave Troll. In his second turn my opponent goes for another Hierach as well as a Mother of Runes, attacking me down to 18. My Troll finds another Troll and an Imp, so I decide to go all in and go for Gemstone Mine into Breakthrough. I find a couple of Moebas and 3 Bridges, so its basicly game over. After sculpting his hand with Therapies I DR for a big Troll and he scoops it up.
Round 3: Affinity
G1: As I know what my opponet plays I lead with Cabal Therapy on my self, to discard 2 Imps. He does the usual Affinity start, with Memnite, Land, Mox, Planting and Frogmite. On my second turn I dredge an Imp, play Colluseum, crack it and cast two Therapys to wreck his hand. He dies one turn later due to Ichorid and Zombies.
G2: We both mulligan down to 5, however I'm still able to lead with a Putrid Imp and a Carefull Study. To speed things up: he doesn't find his hate and dies slowly to Ichorids and Zombies.
Round 4: DDFT
G1: He wins the die roll and reveals his hand, containing USea, 2 Ritual, 2 Petal , LED and Infernal..... nice one.
G2: I lead with a Leyline of Sanctity, he reveals 3 Orim's Chant and we are off to game 3.
Sidenote: We both know each other very well, so we didn't want to waste time watching the other jerking off.
G3: He starts with Top, while I start with a Putrid Imp. He is able to chantwalk me 3 times in a row, while I slowly fill my yard with Therapys. On his 5th turn he goes for a Doomesday, pass. Finaly I get to cast Study and some Therapys, leaving him with lands only. He ponders for a bit, plays Tendrils for 18 and shakes my hand, whew that was a close one.
So I end up 1st, my opponent from round two ends up 2nd and my opponent from round 4 ends up 3rd.

