I'm not sure about Javelins and Horseman Javelins. They are not meant to be used in melee. They are light, fitting for being throw at far distances and with precision. Throwing spears on the other end are heavy, meant to be used against close range enemies and are better as melee weapon (actually they are even better than the normal spears, having a 39 thrust damage vs a 30 of the Heavy Spear)
I think it will be a fair trade if the Light Spears, War Spears, Heavy Spears and the Throwing ones would have the upper attack animation with shields. After all, their reach is usually below the 160, which it's not even the double size of a sword, so they wouldn't be exaggerated.