Macedonian late generals are amazing. With 200 troops per unit, your advantage with javelins really shines in a way that it doesn’t with shock cav. Only so many troops can charge and connect with the enemy at once, but the entire unit can volley together. The ammo is misleading because of the unit size. You have more javelins than any cavalry other than Lusitani light skirmishers. While they lack the shock potential of the early generals, they can hold up in melee or under fire better with their shields. They’re stronger in combat than any light or skirmishers cavalary the enemy can offer. So as long as you keep them away from the enemy’s elite cav and infantry, they shouldn’t take any losses. And that last note is really the point. Macedonia (and Epirus) reformed their general bodyguards because they were losing too many elite troops and nobles (/personal friends of the king) in “heroic” charges.