Introduce Flamethrower with a dragon-head-shaped nozzle, aligning the civ more closely with its gunpowder identity. This might end up being more of a situational unit, even if its stats would be different from the one currently in the Scenario Editor, so I’m not really trying to discuss its impact on balance.
The previous bonus for faster Fire Lancers and Dragon Boats was not very practical. Historically, fire lances were used to fire shrapnel—such as iron pellets or pottery shards—similar to the effect of shotguns. Multi-barreled hand cannons like the three-eyed gun from the Ming dynasty were also employed. Based on this, it would be more appropriate for the bonus to grant gunpowder infantry additional pellets, instead of boosting speed.
They already have strong archers, so having Hand Cannoneers doesn’t particularly affect the balance—at least I hope so.