This sounds bazonic. I feel like an orc is your standard, platonic lvl 1 monster in all editions. Like it's the bog standard that all other monsters are calibrated against.
Encounter building in 4e is much more granular, and more precisely calibrated, than any other edition. Also, monsters are built using different rules than PCs.
So the basic conversion is a level 1 fighter in edition 0e, 1e, B+, 2e, 3e or 5e is the equivalent of a level 2 character in 4e, for reasons that aren't worth getting into. Level 1 is more or less an apprentice level, like UA cavaliers used to have.
The other thing is that a 4e level x PC is roughly equivalent to a 4e level x elite monster. And one level x elite monster is equivalent to two level x standard monsters.
So, assuming characters are not particularly optimized, here is the baseline equivalency: one non-4e level 1 PC = one 4e level 2 PC = one 4e level 2
elite monster =
two 4e level 2
standard monsters. Where "not particularly optimized" in 1e means your aren't using UA rules.
Like 3e and 5e, 4e encounter building guidelines skew toward not particularly dangerous fights. So a level 1 encounter for a party of 4 PCs could include four level 1 standard kobolds, which group has half the power of four level 1 PCs. Whereas a group of eight level 1 standard kobolds would have a roughly even chance of winning against a party of four level 1 PCs.
So a 4e level 3 standard orc is still less powerful than a 4e level 1 PC by a significant margin, maybe 3:4. But a level 3
elite monster would be much more powerful than a level 1 PC, say 6:4.
It works out like this:
4e level 8 minion monster (88 XP) = one 3e kobold, or one 3e CR 1/4 monster
4e level 1 standard monster (100 XP) = one 1e kobold, or ~1.1 3e kobolds
4e level 2 standard monster (125 XP) = one 1e or 5e bandit, or one 3e goblin warrior, or one 3e CR 1/3 monster
4e level 3 standard monster (150 XP) = one 1e goblin
4e level 4 standard monster (175 XP) = one 1e orc, one 5e goblin, or one 3e CR 1/2 monster
4e level 5 standard monster (200 XP) = one 1e hobgoblin, or one 4e level 1 elite monster, or one 4e level 1 PC
4e level 6 standard monster (250 XP) = one 1e or 3e gnoll, or one 3e CR 1 creature, or one 4e level 2 elite monster, or one 4e level 2 PC
4e level 7 standard monster (300 XP) = one 5e orc, hobgoblin or gnoll, or one 4e level 3 elite monster, or one 4e level 3 PC
4e level 8 standard monster (350 XP) = one 3e bugbear, or one 3e CR 2 monster, or one 4e level 4 elite monster, or one 4e level 4 PC
According to 4e encounter building guidelines, for a party of four level 2 PCs (equivalent to level 1 in any other edition), an
easy encounter would have monsters worth roughly 88-100 XP per PC, say 4 1e or 3e kobolds for a 4 PC party. Which is pretty easy.
A standard encounter would have 125-150 XP of monsters per level 2 PC. So say 5-6 1e kobolds, or 4 1e bandits, for a party of 4 level 2 PCs.
A hard encounter would have 175-200 XP of monsters per level 2 PC. So 7-10 1e kobolds, or 6-8 1e bandits, or 6-8 3e goblins, or 5-6 1e goblins, or 4-5 1e orcs or hobgoblins, or 3-4 1e gnolls, for a party of 4 level 2 PCs. The higher end of that range is very dangerous for the party if they haven't been conserving resources.