Firewarriors are one of two Troop choices available in Codex: Tau Empire, and as such their main role will often be capturing and holding objectives. Firewarriors are not naturally a resilient unit however; their low toughness and middling save cannot protect them against sustained fire.
Properly supported and augmented, Firewarriors can be decent objective holders. Leadership support is essential, whether it comes from an Ethereal’s area of effect, an attached independent character, or a Shas’Ui within the unit. Depending on the opponent, Firewarriors may need to stay in cover - but in some cases there will be a lack of AP4 weaponry available to fire on them and they will be able to operate out of cover.
Firewarriors are also slow-moving on their own. Devilfish transports can be useful in getting Firewarriors where they need to be if objectives are located mid-field and are unapproachable until the late game. Devilfish transports are also very durable and can protect Firewarrior squads until they are needed to claim objectives.Firebase:
Firewarriors can also be a significant source of firepower for a Cadre. Pulse rifles are relatively long-ranged, and can effectively engage light to heavy infantry. Firewarriors are most effective with markerlight support, although care should be taken not to over-spend markerlight tokens on Firewarrior teams, especially when removing cover, since many enemies will prefer their armor save to cover anyway.
Firewarriors in a firing line can be most effective in close ranges, under 15", where pulse rifles are in range to rapid fire. Augmented by an Ethereal or Fireblade, Firewarriors can lay down an intimidating barrage at close range.Strike Team:
A more unorthodox use of Firewarriors is their deployment in aggressive close-range shooting attacks. Firewarriors loaded onto devilfish can move/disembark within a range of ~12" and rapid fire with rifles another 15", or fire two shots with pulse carbines at 18", for a threat range of 27-30" after movement. Augmented by firepower-enhancing Independent characters such as Ethereals or Darkstrider, a Firewarrior team can become deadly. The inclusion of Darkstrider in a Firewarrior Strike Team also allows the team to deploy via outflank, putting enormous sections of the board within the threat radius of the unit. This deployment can even be used for the attacking and claiming of objectives in enemy territory. This aggressive style could expose Firewarriors to assault and close range retaliatory fire, however.
Firewarriors equipped with EMP grenades and pulse carbines, referred to as "EMP commandos" are close cousins of Firewarrior Strike Teams. They are also deployed aggressively, sometimes in Devilfish for close-up attacks against the enemy. They can be extremely effective against vehicles, if they make it into assault.Relevant Firewarrior resources on ATT:Darkstrider ArticleCommando Cadre Tactics