4Game

Let me first say parry is awesome and discuss its value. Parrying is generally the "meta" way to go as a parry (while costing a little more stamina than basic block) generates:

1.Free time and stamina during stagger where enemies cant attack you to make you lose stamina by blocking or dodging.

1. Boosted damage during stagger which also makes your dmg/stamina ratio very good.

2. The best possible block values even over tower shields due to 2-2.5x bonus to block values during a parry.

This is fun and rewarding but leaves the tower shield in the dust; requiring longer fights, greater stamina usage despite lower initial stam on blocks, and over all weak blocking in the places id personally expect to need or want tower shield (heavy heavy hits) due to less block value than multiplied out parry power.

THE IDEA:
While blocking with a tower shield, increase the point of diminishing return on armor (when armor = 50% of damage) by a flat 8.333% per upgrade level of tower shield. Thus, blocking with a tier3 tower shield would increase armor's diminishing point to 75% (50% + t1 8.333 + t2 8.333 + t3 8.333) of dmg rather than 50%.

Closing notes:
This keeps the game mostly the same on weak to mid ranged damage enemies and simply bolster's the tower shield when engaging extremely heavy hits. Trading slow, low damage, stamina exhaustive fights for a more pleasant return in survivability against the big boys.

All criticism welcome. Numbers may need tweaked for balance and intended purpose.