Arrows vs shields in dom2 and dom3

[Corwin]

I assume the shield works the same way for all missiles, including crossbows, javelins, etc.
Which in some cases doesn't make much sense, IMHO.

For example. let's say the gaint has trown the boulder into the Ermor's undead legionarie. Legionare has 5 HP and tower shiled. Instead of being smashed to fine bone dust by the force of impact, according to above formula the legionare have 97% chance of avoiding any damage from huge boulder thrown by giant due to legionare's tower shield.


Also what about magical missile-style attacks? Like Yomi's "thrown flame"? Is it also calaculated the same way as arrows? (plus 2 to hit perhaps for being magical)