Sword may be nice, but I find spear is very useful, it's cheap, and easier to make for trained troop...I do like many archer with few spearmen to back them up. I love this style! Swordmen is nice, but it's too much resouce (weight for troop, yikes) and long build... I find spear better, it's very light weight and not worry about counterattacks, had a simple ignore a significant part of enemy defense , had a shorter training troop but it's may not stop maul, but not worry about it if archer do job well before something or someone come to spearmen...
I do love spear, I do like sword very much, but not this game thank to spearmen and archer, too many game spear isn't very useful (I don't know about those total war medival time or total war rome time)
Now this game spear is almost like a real world, it's easy to training, cost low, and done good job in damage even armors, simple poke in right way...if done a right way, because in real world armor do had weakness spot, not all cover human body...
I don't use single hand spear, because I don't want too heavy on troop, I like troop had lot of turn and fast, that's why I don't see single hand spear because sheild is too heavy...