Weapon Type vs Armor Type

[Solomoriah]

DMG page 28 specifically says "armour type" and not class...
"
Weapon Types, 'To Hit' Adjustment Note
==========================
If you allow.... be certain to remember that these adjustments are for weapons versus specific types of armor, not necessary against actual armor class. In most cases monsters wearing armor wil not have any weapon type adjustment..."

I could NOT find that this morning when I looked for it...

weapon vs armor types is a mess

what would work a little cleaner and IMO much better would be some general armor types vs some general weapon types (really rough thoughts below):

Armor type
plate: +vs bludgeon. -vs piercing. no adjust vs slash.
chain/scale: no adjust vs bludgeon. - vs piercing. + vs slashing.
leather/hide:

The list could be expanded with more weapon/armor types, and further adjustments for more weapon types.

More or less what 2E did.

It seems to go like this:
10 No Armor
9 No Armor and Shield
8 Leather or Padded Armor
7 Studded Armor or Leather or Padded Armor and Shield
6 Ring Armor or Studded Armor and Shield
5 Mail Armor or Ring Armor and Shield
4 Banded or Splinted Armor or Mail Armor and Shield
3 Plate Mail Armor or Banded or Splinted Armor and Shield
2 Plate Mail Armor and Shield

Exactly so.

Never bothered with this or speed factor.

We used speed factor only when initiative was tied. Never actually used weapons vs. armor type.