>I'm not even sure how that leaf spear is suppose to work.
If you look at the Mandarin Duck formation, it shows you a squad of soldiers that work in cooperation. Each soldier has a different weapon for a different task. The problem this formation has however is that it is weaker against full spearmen formations and cavalry attacks. To compensate for that they gave the spear of the single spearman in the unit more points ends. Put several Mandarin Duck formations side by side and the spearmen together create a pointy metal hedge against oncoming attackers.
>some of those look straight out of ye olde first 3d wrpg
They don't just look like that, old first 3d wrpgs did indeed copy weird blades from around the world to look more exotic and fantasy. On top of that the Philippines in the 90s had some influence as the cool hip thing in martial arts. Richer Generation Xers would travel there for sex tourism and flex on their peers that they trained there in knife fighting or some other martial arts, which wasn't your old and stale judo, karate or kung fu you could trains in the West.