To see if my build is still working for me, in light of others making changes, I thought I'd do the old 10 games in a row myself and see how the posted deck holds up as I haven't played it in a while (been having a serious love affair with the Infinite Turns deck...)
1) Tokens. The Rabblemaster is too fast for Jade Mage to keep up with and by the time he drops a Phantom General, his tokens are all dead. Turn 5 I have a weenie army including Wayfinders, but can't get 5th land for a Prowess or Wrecking Ogre for the kill, so double Unearth instead to take him to 4 life, then overrun him next turn. 1/0.
2) Artifacts. Arsonist and Rabblemaster hand again, which handily outraces a Glaze Fiend. Turn 5 win via Stormbreath. 2/0.
3) Spell Triggers/Tokens. Solid 2 mana Guildgate hand with Wayfinder, Anger, Unearthers and Rabblemaster. He kills the Rabblemaster, I Spawn for 5 instead of killing his Skulker, he grows it then casts Blasting Station to split it. Turn 6 Stormbreath, then turn 7 Bloodrushed Dragon over the Squids. With Anger as a backup, I was always confident. 3/0.
4) Control. I take a needlessly risky hand of Assault, Nemesis and Prowess, but draw good stuff. He just drops defenders, and I Mycoloth an Arsonist when he taps out that he can't deal with. I eventually Prowess it when he next taps out to make a 9/9 trampler and attack with a Nemesis too, which dies, but I draw 5 cards and leave him with just a Talrand. I Assault it next turn, no counter, so I Prowess a second time and kill him. 4/0.
5) Rematch! Battledriver, Mycoloth and 2 x Spider hand. No sac fodder or graveyard fillers, so risky, but I know he's slow so will chance drawing into them. Luckilly he gets mana screwed. T3 Arsonist. T4 Battledriver. T5 Battledriver(!). It takes me until T8 to draw a 5th land, but Hellsparks and Wayfinders do me proud. T8 Mycoloth, T9 Spiders = Carnage! 5/0.
6) Goblins. Arsonist is a good card here, but double Hellsparks less so if I need defence. T1 Quest for the Goblin Lord gives me worries. Thankfully he took it due to a Rabblemaster and is punished by missing two land drops. I try to race with Hellsparks, which actually take 12 life off him, but my 5th land takes FOREVER and I need to Spawn or I die. He taps out and throws everything in to take me to 2 life with just a Guttersnipe blocker and 8 life. I have just an Arsonist, he declines to block (maybe anticipating a Spawn?), WRECKING OGRE FOR 8! No Spawn needed! 6/0.
7) Auras. Mycoloth, Assault, Rabblemaster in hand, 1st draw Stormbreath. Feeling good! He Assaults my Rabblemaster, and I Stormbreath instead of T5 Mycoloth in case he Shocks my single Goblin token pre-Devour. He enchants a Gnarlid, making it a 5/5, but rather than kill it, I Bloodrush Stormbreath to deal exact fatal damage at 14 on T6. 7/0.
8) Rematch! I manage to T3 Nemesis off a T2 Wayfinder. He double Gnarlids, but I decide to race instead of using the Nemesis to block posible enchants. He loses a Gnarlid in combat, then eventually kills the Nemesis next turn via Titanic Growth. Rabblemaster T5, which is Assaulted, Stormbreath T6, which is Banefired, however he now has a lone Gnarlid blocker which can't survive a double Unearth and weenie attack. 8/0.
9) Weenie w/ pump spells. 2 x land, 2 x Wayfinders, Hellspark, Assault and Prowess. We trade early blows, I have two Wrecking Ogres but Prowess T5 instead as he has two Squadron Hawks for my two Wayfinder attackers, and I don't want to waste it if he decides to trade. T6 I Mycoloth an Arsonist to kill an Akrasan Squire, but leave the Wayfinders as I fear Reprisal and want Ogre vehicles as he's on exactly 8 life. He chumps the Mycoloth, but lets the Wayfinders though as he wants to save his Hawks as I'm on a 2 clock. Bloodrush - victory! 9/0.
10) Mill. Excellent hand. 3 lands (2 Shardlands) Wayfinder, Spiders and a Nemesis! He T1s a Crab, T2 landfall mills me, then plays a Tome Scour on me. Oh dear! He doesn't adapt his strategy despite a Spawn and Unearthers hitting my yard. T3 Nemesis, T4 Monstrous when he declines to chump with the Crab for 10 damage. Realising his error, he holds back blockers next turn (including 2 Triton Shorestalkers). I have two Wrecking Ogres, but T5 Prowess creates a 13/13 trampler, plus a Wayfinder attacking, and it's game on T5! 10/0!
Conclusion: The 5 mana spot is quite crowded, and if you lose your early beats, you can be in trouble. Waiting to get there can be pretty rough at times. When you do though, you can often finish them pretty quickly, and the Thrinax would obviously help you get there a lot safer. This has made me realise that the 5 mana hump is an issue though, but the sheer threat density when you get there is amazing. The Thrinax is a legit change I feel, but Prowess and Wrecking were responsible for 6/10 of my victories, with the Ogre an astonishing 4 of them (though I did draw it early in every game weirdly enough, and hardly saw Anger of the Gods which is the same rarity...)
Personally I'd remove the Nemesis if pushed. It's a great card, but trading a creature for a creature is fair, especially as both are ideally T3/T4 drops and serve as similar early roadblocks for the opponent. You lose some aggro and Prowess combo potential but trade that for defence, Mycoloth and Wrecking Ogre potential, so it's a good trade. Possibly even an optimal one.
The main issue with such a swap though is it reduces your Anger of the Gods equity, One great aspect of the Nemesis is you can wipe then throw in, whereas the Thrinax won't even split in response. My card choices in my decks are usually pretty layered and purposely chosen for synergy reasons rather than mainly considered for curve and such, so substituting anything can have a mild to serious knock-on effect on the effectiveness of the rest of the deck.
Still, the Thrinax is definitely something to consider I feel. I don't think I'm missing out on Shadowborn though.