User blog comment:MeDeoPal/On the Origin of Titans and Shifters/@comment-179280-20130823001810/@comment-137.166.149.51-20130908033907

I guess they were built to be powerful but they need a self-destruct button, just in case, things went nasty...... that is why they have a weakness in the nape and the need for sunlight in order to function. There are different titan shifter and many of them seem to be built in a different way.... Colossal titan may have been built to be huge and were meant to be use for siege purpose, Armoured Tian maybe used to function as battle tank and be used against infantry but weak against Ttian that are strong in close combat such as Erne and Annie. Annie maybe built for long distance pursuit, Ymir maybe built for scaling walls and higher terrian. Eren maybe used for assault shock troops and be built as an anti-Titan weapon, based on how he deal with Reiner. Based on what I have observe. The smaller one maybe used to assault soldiers in smaller building. The rest are just regular titan.