bruiser arena/joust

Swap Deathbringer for Heartseeker in the 1st build.

Not sure what exactly is going on in the 2nd build, which looks like a tragedy.

Aside from the comments on crit already, since Herc is more ability based you really don't want to go AA on him anyways, do you? I mean he does hit hard to start but his abilities don't really support his AA's like some of the other gods do. Aside from the deathbringer at the end of the first build(not going to discuss the second build), my main concerns with it are:

1. If i am going CDR i would rather have it from BoV on him rather than Prid. His ult isn't really one where you have to be in the middle of the other team to use, so it isn't as imperative that you have a shield for getting away or finishing once you hit your ult. He also has his dash, so you can always hit with the ult and then dash away if you need to. If you have Regrowth that early you can also pop your heal and speed away even faster.

2. I have used Regrowth that early and it can be good, but I usually don't like to put it that early because instead of building to his strength early game, you are taking away from it.

A few kind of examples of how i like to build him in arena
Warrior Tabi Blackthorn Hammer Genji's Guard Breastplate of Valor
Warrior for the best base damage boost, blackthorn for the extra power and utility from cdr or mana regen, i go genji's next a lot depending on magical threat(extra mana regen and more cdr). If you want to cap your cdr in arena then BoV at the 4 is one way to do it.
rounding out this build you could go more aggressive or conservative
5 and 6 aggressive options Masamune(don't see that a lot around here but has worked well for me at times) Shifter's Shield Void Shield Brawler's Beat Stick

5 and 6 conservative options Spirit Robe(usually better early, like in the 3 if used, but can work late) oni's hunter garb Mantle of Discord Magi's Cloak(don't see this on herc a lot but can be useful with super heavy cc)

Going this way you wouldn't have room for regrowth unless you used an alternative health/power item like Frostbound Hammer at the 2(which isn't very popular but i have found can work) you could also stick with regrowth at the 2, but again, you are taking away from his early game strength.

If want to have shield of regrowth later, then I might go, depending on situation Pestilence, Bulwark of Hope or Runic Shield in the 3rd slot and then go regrowth at the 5 spot.

I find that a lot of times I am fine with 20-30% cdr on him so if you don't want to restrict your build by cdr as much and also build into his power early it can be pretty easy. Depending on how the match is going something like these can work.

Warrior Tabi Blackthorn Hammer Masamune Hide of the Urchin shield of regrowth Shifter's Shield

Warrior Tabi Blackthorn Hammer Void Shield Genji's Guard shield of regrowth depending on match Mantle of Discord Shifter's Shield Brawler's Beat Stick

support your healing/group healing
Warrior Tabi Gladiator's Shield Genji's Guard caduceus shield Ancile at the 6 shield of regrowth, Mantle of Discord, or Blackthorn Hammer. you could sell gladiator's shield late depending on what you need, so you could still get two of the 3 items i listed here for your 6 if time permits or something else you might feel you need as a specific counter.

Remove crit