A proposed 170-gun three-decker at Trafalgar

How would the proposed 170-gun three-decker fare against the French and Spanish at Trafalgar?

It would probably become Nelson's lead ship and impose overwhelming local firepower on the Combined Fleet.

The proposed 170-gun three-decker is imagined at the head of the British line at Trafalgar, although its name is unclear in the recorded question. Nelson would probably choose it as his flagship because its size and strength would let it force a passage through the enemy line and keep going. The hypothetical also includes Seppings-style structural improvements, strengthening the case for using it to lead the attack. Its appearance would overturn French and Spanish expectations that they possessed the largest ship in the opposing fleets.