Pila/throwing spear oneshots feel just as bad to infantry as they do to cav. Imo throwing spears shouldn't exist with current damage numbers.
The sturgian and battanian throwing spear is a better cav melee weapon than all other spears, which is itself ridiculous.
Make the throwing damage be about 70-80 to low armour inf, or about on the level of jarids or slightly higher, and make melee damage on par with other spears.
Throwing spears/pilas should be taken for their versatility as a both a melee and throwing weapon. If you want throwing, you should prefer to pick dedicated throwing perks instead.