That’s certainly a good argument for giving them something to help with cav, but not necessarily the Luojuzi, which already carries a strong anti-archer and a decent anti-infantry role on its shoulders. If anything I would give the Raeu Tribesman some anti-cav bonuses, as it otherwise appears to be an extremely niche unit.
This suggestion does make some sense. So how about removing the +3 bonus against Spearman for the Luojuzi, making it a more dedicated anti-archer/anti-cav unit, and then give the Raeu Tribesman some anti-light cav bonus (not against all cavs, only against light cavs or the scout line)? Here’s what the result looks like (also decided to increase the gold cost of Luojuzi from 25 to 30)
Luojuzi Stats
Cost: 40 Wood 30 Gold
HP: 35 / 40 (elite)
Attack: 4 / 5 (elite) pierce
Attack bonuses:
+4 / +5 (elite) vs Archer
+3 vs Cavalry Archer
+2 / +3 (elite) vs Cavalry
Rate of fire: 3.05
Frame delay: 20
Range: 5
Minimum range: 1
Accuracy: 95%
Projectile speed: 7
Melee armor: 0 / 1 (elite)
Pierce armor: 4
Armor classes: Archer, Unique Unit
Speed: 1.2 (not affected by the civ bonus as it is a skirmisher)
Raeu Tribesman stats
Cost: 40 Food 20 Gold
HP: 60
Attack: 8 melee
Attack bonuses:
+3 vs Ship
+3 vs Fishing Ship
+2 vs Light Cavalry (the scout line)
+2 vs Eagle Warrior
+1 vs Standard Building
Rate of fire: 2.0 / 1.6 (on elevated and marshy terrains)
Melee armor: 1
Pierce armor: 3
Armor classes: Infantry, Unique Unit
Speed: 1.1
It’s hard to be supremely confident in my conclusions, since there’s a lot about a unit that both designers and commenters can miss when they can’t actually play around with it, which is why I included playable scenarios with my first designs, so people could at least have a scenario-level understanding of the unit.
The Youtube user MantisAoE has designed a unit for his Zapotec civ called the Owl Warrior, which is very similar in concept to the Luojuzi, being a fast skirm with a slight anti-cav bonus. You can watch this video to get a sense of how such a unit would look like and perform in a game (the stats of the Owl Warrior are shown at 5:52)
https://www.youtube.com/watch?v=W2y2QZP_oQU&t=2s