This is a running theme with my gallery now, it's either endowed females or skilled combatants. (Are warriors a fetish?) Anyway, thought process:

Yinglets. Heartbeat rate and breathing rate of hummingbirds, good for bursts of energy and reaction times, bad for long term combat. Have to strike decisively instead of wearing enemies down through attrition. Flight side of fight or flight but disregarding that because that is shameful to the halls of Valhall-- I mean my gallery. Very fast, despite lack of agility, so similar to cheetahs.

Conclusion: Lance cavalry-like weapons and tactics. A war horse would weigh roughly 550 kilograms we'll say. Moving at 40km/h (~11m/s) that's impacting a force of 33,275~ Joules. That's about 23,000~ ft/lb's of force.

A yinglet is not nearly as heavy, but the principle remains the same only with more emphasis on acceleration making up for mass, the couched lance will put the yinglet's incredible running speed to work (as well as let them reach up to taller targets). I actually modelled his armour off of horse armour, as well as given a shoulderpad/cavalry heater shield on the offhand arm. Their tactics would be to try to hit enfilades as best as possible. Very risk/reward combat. Losses from tactical or strategic errors will be magnified.

Yinglets are from  valsalia