My simulator found the problem; this piece is about how I decided what to do with it.
Screening every legal 5v5 matchup flagged 66 dominant teams — and one placeholder module, Fast Taunt Tank, sat in all 25 of the top 25 risk teams. Its Ultimate taunted the entire enemy team for 2 turns with cooldowns frozen: other teams were locked out, and the only "counter" was running the same module yourself. A mirror isn't a counter.
I tested the cheap knob first: cutting all taunt durations to 1 turn dropped dominant teams from 66 to 36. Real progress — and the wrong fix. It made taunt too cheap everywhere. The team-wide taunt was still great; single taunts became meh. I wanted taunt to matter, even single taunts.
So the rework was a trade. The team-wide taunt died. Single taunts kept their full 2-turn punch, and S2 became a second single taunt aimed at the fastest enemy, so taunts can drag any role into the fight — not just the biggest attacker. The Ultimate got 120% full-AoE damage and a DEF debuff back, because it still had to feel like an ultimate.
Verified with ~194,000-battle controlled A/B packets per variant: 66 → 36 → 27 dominant teams, counter availability up from 31% to 40%, defender hold down from 69% to 60%. Recorded as YELLOW — provisional on purpose, with the remaining 27 packages on a watchlist. Counterplay surfaced. Taunt still matters.
(Fast Taunt Tank is a placeholder test module, not a shipped hero. The measurement pipeline behind these numbers is its own case study on my profile.)

A balance design case study: how one placeholder tank kit got rebuilt, and why.
Check the claims yourself — code, gate records, and evidence: https://github.com/cody220022-jpg/idle-rpg-combat-sim-showcase