Are these cards something like event cards, that you draw each time you enter a room? If you use them as treasure cards, because I think the wondering monsters are enough in the treasure deck, I am sure your game will going to be very hard or no-one will search for treasures anymore.
With “D3 orcs” do you mean 3 six-sided dices?
The cards are nice but in my opinion it is better to make some monstrous tables, and roll polyhedral dices to check the results. Some nice tables could be very useful for quest creation and for stocking the dungeon. For example, an easy/normal/hard undead monster table, and an easy/normal/hard beast monster table with 10 encounters each could be more than enough.
A fast example:
Easy Beast Monster Table (1d20):
1: 1 Goblin
2: 2 Goblin
3: 3 Goblin
4-5: 1 Orc + 3 Goblin
6-7: 2 Orcs
8-9: 3 Orcs
10-13: 4 Orcs
14-16: 1 Fimir + 1 Orc
17-19: 2 Fimirs
20: 3 Fimirs
...And no need to make them very balanced. Sometimes is charming to play against unbalanced rules.