I don't see Goblins having magic items often. "Vicious Weapons", (as per the PHB), poisons and traps, yes, but not magic items. I do believe that they'd make heavy use of their environment to augment their abilities. For example, keeping animals and insects to harvest poisons, using animals and insects in attacks, and utilizing disease-causing filth in attacks and traps.
For example;
-Goblins are launching baked-clay globes at the party from some sort of large slingshot. On a successful hit, the globes do 1d4 dmg and break, releasing a swarm of (whatever insect sounds fun at the time). For flavor, some of these globes are full of "filth"; on a hit, PC's make a CON save or vomit uncontrollably for a round.
- Goblins rush your party with jagged scimitars. Each blade is coated with the poison of some mundane animal from the MM, or smeared in miscellaneous goblin "filth". On a successful hit, PC's make a CON save or contract some sort of disease or poisoned state.
-Goblins are hurling javelins! On the upper shaft of each javelin is tied a tiny poisonous snake! 25% chance PC struck by javelin is bitten.
etc, you get the idea.
I essentially play Hobgoblins as a monstrous Roman Legion, putting more stock in group discipline than individual prowess, so while they would value +1,+2,+3 weapons and armour, I would likely embed some "morale" magic items with them. Anything that would aid the legions in holding the line would be valued. (enchanted banners, horns, etc.)
Orcs get magic weapons from their gods and Shamans, or straight up steal them from the people they kill.
