[trebuchet]

I haven't tried this exactly, but something close enough that I'm convinced it's feasible.

Exercise: take javelin-equipped light infantry, position them far up to the front, with your heavy infantry staggered just slightly back. LI orders to fire closest, HI ordered to hold and attack closest. The javelin volleys are usually about done around the time your HI engages. If the LI does happen to get engaged too quickly, depending on their morale they will either stick fast (and your HI comes in from the flank), or break and run. The fleeing LI will often take only minimal casualties, leading the enemy troops on a wild goose chase.

But in either event, a close range javelin volley can be devastating to independents which normally would put up a tough fight.

Then again, Ermor/Pythium LI is probably superior, so your mileage may vary.