No, you're still not getting it. Siegfried has an active skill that multiplies the next attack's damage on a stunned target (4x for a normal attack, 3.5x for a Burst attack). So optimal use of Siegfried (assuming a fully limit-breaked SSR main-hand weapon) requires timing the Burst so it lands while the enemy is stunned. But if another Siegfried Bursts first, the enemy will instantly recover from Stun, nullifying Siegfried's DPS advantage.