Umm...I am not a modder, so I know nothing about the animation and stuff, but I THINK I can provide a might-be explanation on the topic that why there is no spear in the game. First we will have to take a look at the horses. If you bought in an ordinary horse at the stables, you can see that all stables horses are not equipped with stirrups. Which means that the saddle is Rome - Gaul style. In Roman times, when stirrups didn't yet exist, saddles have "bumps" at the corners to hold the position of the thigh when riding.So we see that the game, riders, ride mostly slowly and will have to fight off their horses. On the other hand, precisely because war horse can not play, so in Skyrim, long thrusting weapon used against cavalry are not needed. And dealing with the enemies with the kind of the saddle they are on, long-handled ax or two-handed will be enough. Just my own opinion, though.
