That's a VERY simple (and classic thing), but it could help.
Just a plain, simple "orc barbarian 1"
With their +4 str, even with low point buy they can get 18 str. Let's give them greataxes.
They're a CR 1 monster that, when raging, have a +7 on hit and deal 1d12+9 damage.
I think that they could be "mooks" that can be relevant even at level 5-6, being able to hit AC in the low 20s without too many troubles, and dealing about 15 damage on every hit.
A greater barghest could be a cool "boss" to them, since he can buff them pre fight with Mass Enlarge Person and Mass Bull's Strength.
Buffed, those orcs would hit with a +9 bonus, and deal 3d6+13 damage.
Sure, they would be easy to hit, be vulnerable to sleep or mind affecting spells, but when they hit, they'll hurt.
Instead of orcs, we can use Goliath and stack Mountain Rage and Reckless Rage. That will give an impressive +8 str bonus on them while raging.