Originally Posted by
Sar1n
Guard mode is very important for fighting in spear wall. When on, the unit acts as a "brick", keeping the enemy at pike length, sticking to the formation and not causing many casualties, but not taking many either, at least from the front. When the guard mode is turned off, the troops will actively try to stab the enemy, causing more casualties but letting more enemies through to close combat, and they won't hold the line perfectly and creep a bit forward when in contact with the enemy.
Because M2TW spear wall is hardcoded to use only first three ranks, the best use is to create thin, only four or five ranks deep line with guard mode on to take enemy charge, pin them down in place and exhaust them so the ranged units and flankers can do their job. Due to their unit size, they can pin down disproportionate number of enemy troops, giving you the opportunity to overwhelm the enemy elsewhere. Once the ranged troops did their jobs and flankers are attacking the pinned enemy, just turn guard mode off and watch the carnage. Enemies pressed by phalanx from the front and other unit from side or rear break quickly.
In towns, don't use them on walls. They're hopeless. They can deal with ranged units forced into melee, but any decent infantry, even light like Promachoi or Leginu will chop them down. Don't turn spear wall off if you want them to be of any use.
Down in the streets, they're actually good. Because M2TW allows two units to overlap, phalangitai are great force multipliers in a "blob" clearing the streets, as they can reach the enemy while still behind the first line of troops that's in contact with the enemy. Just toggle guard mode off for that. They won't do it if they're not in spear wall though...