I used shieldwall in a version of RTR and it made hoplites too hard to attack. If I remember they formed into a box with spears pointing outward. Not exactly shiltron but you couldn't flank them at all. It doesn't matter too much to me since the game's mechanics makes them get shredded by swords. It's best to focus on flanking with assault troops or heavy cavalry. Anyways I like the not quite perfect formation. It would seem robotic if they kept perfect form all the time. In the heat of battle soldiers fought to keep formation while trying to save their skin too.