OD&D Monster Level Tables

Looking over pages 10 and 11 of Vol. 3: The Underworld and Wilderness Adventures, I'm beginning to notice that dungeon level in OD&D does not necessarily equal the appropriate character level. On level 6, for example, a group of character may regularly encounter 1-8 giants, a 9-12 head hydra, 1-6 basilisks, 1-4 gorgons, 1-4 chimeras, 1-6 vampires, lords, balrogs, wizards, evil high priests, and 1-4 purple worms. I'm not sure a group of 6th level character can really take those on with much chance of survival.

However, myrmidons (6th level fights) can be found on level 4 and enchanter (6th level magic-users) on level 3. Bishops are not included on the monster level tables. This I would guess that levels 3-ish to 4-ish are more suitable for a group of 6th level characters. Similarly, Men and Magic provides rules for characters up to 12 level (wizards), but provides only 6 levels of monster tables.

Based on pages 10 and 11, here is my best guess at to suitable dungeon levels for players characters in OD&D:

Dungeon Level 1 - 1st & 2nd level characters

Dungeon Level 2 - 2nd & 3rd level characters

Dungeon Level 3 - 4th to 6th level characters

Dungeon Level 4 - 6th & 7th level characters

Dungeon Level 5 - 7th to 9th level characters

Dungeon Level 6 - 8th to 12th level characters

What do you guys think?