**Totally disagree, with their 4+ to hit they are one of the last unit that do not hit on 3+ in the army, for the same price you can have Hearthguard Berzerkers that have a 4+ FnP, hit on 3+ and have flat 2 damage. They are a good support (especially against monsters where they gain a nasty +1 damage) and they can protect heroes (intercept wounds on 4+) but they will struggle to hit enemy heroes with the -1 to hit from Look Out Sire!, you have no way of making them battlelines (Wrong, Runemaster as General), they do not benefit from some of our runes that affect only melee weapons and they will die fast in close combat.
*'''[https://www.games-workshop.com/resources/PDF/AoS_Warscrolls/AoS_Fyreslayers_WSCards_Hearthguard_Berzerkers_EN.pdf Hearthguard Berzerkers]:''' (120 pts, min 5, 600 pts, max 30) Per the new Battletome, Hearthguard Berzerkers may have arguably seen the biggest improvement out of the whole book. Hearthguard have a nifty ability to ignore wounds and mortals wounds on 6's, and this is increased to 4's when they are within 10" of another Fyreslayer hero. In addition, Hearthguard come with two wounds and two attacks base on all their weapons along with 2" reach. Their Berzerker Broadaxe has better Rend and damage than the Flamestrike Poleaxe, but the Poleaxe has the potential to deal 2 Mortal Wounds on top of normal damage on 6's to hit.
Always take the Broadaxes for their better damage output against 3+ and their stability, except against armies with unmodifiable saves such as like Nighthaunt or Idoneth Deepkin. Overall, a very powerfull unit that surpasses Vulktite Berzerkers, while maybe lacking some of the reliability of Vulkites thanks to their better armour save in combat and ability to attack after perishing. The Hearthguard Berzerkers are there to smash through any enemy lines and tank enemy attacks with their extra save after the save. Always remember to keep a hero nearby at all times as they lose a lot of their surviability without it.
** Don't forget we have easy way to give 3+ save (Battlemith + prayer), and even 2+ with the Runesmiter. Now take a unit of 30 (they have the horde reduction cost, unlike Vulkites...); with a 3+ (or 2+ for 1 turn) save and a 4+ FnP, they will not die easily, and they will hit like a truck in return: 2 attacks each 3+/3+/-1 2d, with a range of 2", they can fight on 2 ranks... this is borderline nasty (without even including our runes, you know like rerolls hit roles of 1 or add -1 to Rend...). And you can even give them rerolls all failed wounds rolls, and making them attack twice in the combat phase with a Battalion (if anything survives the first wave to begin with).Vulkite and Auric are good, but Hearthguard Berzerkers are really, really, good. And oh, we can make them battlelines with a Runefather as general.