Mostly the weighting of killy vs survivable is very unfair for WoC- you have expensive models and so most people you face will have very much larger units then you do.... so surviving might be great, but you'll never get through their unit. So winning the fight isnt really the aim, killing enough models to strip them of their steadfast is. This means MoK or banner of rage is an excellent start to a unit... but shield, AHW or halberd each have their own uses (although if you are looking for a bunker for a character then a MoT shield unit of warriors is awesome).