6 Legion
In the early days of Season 5, the 6 Legion composition was incredibly strong with both offensive and defensive capabilities above average. With a high attack speed at the 6 Legion threshold, the units of this system had an excellent ability to deal damage over time. Moreover, champions like Mordekaiser, Aatrox, and Riven had relatively solid survival tools in the mid-game. However, with the release of patch 11.9b, the 6 Legion composition has almost completely disappeared from the meta.

The biggest reason for this is that Mordekaiser’s output damage was reduced too much. Alongside the nerf to attack speed at the 6 Legion threshold, the magical damage on Mordekaiser’s attacks is no longer substantial. When damage is reduced, the weakness of the Legion composition, which lacks strong defensive effects, gradually becomes apparent, making these units too easy to take down. Perhaps you should only pursue the Legion composition if you can upgrade Mordekaiser to 2 stars early in the game.
Sharpshooters
Regardless of the variant, Sharpshooter compositions revolve around one principle: playing around Aphelios. This unit can deal extremely strong damage to both the front line and back line, allowing Aphelios to “carry the team” effectively when equipped with the right items. The downside is that the Sharpshooter composition is overly dependent on Aphelios alone, lacking other damage-dealing carries. Once this unit is nerfed, the entire Sharpshooter composition becomes significantly weaker.

In the recent patch 11.9b, the slight reduction in Aphelios’s physical damage and base attack speed caused Sharpshooter compositions to vanish from the meta. The advice is that you should not build a Sharpshooter composition at this moment as it is too risky and its power in the late game is not significant enough. If you have Vayne early on, consider building a Reaver composition with dark items like the Hextech Gunblade and Runaan’s Hurricane instead of trying to play 4 Sharpshooters.
6 Warriors
Although not nerfed in patch 11.9b, the 6 Warrior team is gradually disappearing from the Teamfight Tactics meta. As players recognize the immense value of Rell, this champion has become a highly contested unit. Thus, the chance for Warrior players to acquire this unit has become much harder. This makes the defensive capability of this composition extremely weak, and the core units are too easily defeated.

Moreover, as team comps that focus on protecting backline carries gradually dominate the meta of Season 5, melee-based compositions like 6 Warriors face significant disadvantages. Players using the 6 Warrior team often find themselves helpless as they watch their carries get crowd-controlled and taken down one by one. Perhaps the winning condition for this composition is that players must possess 3-4 Quicksilver items, which is very rare.