Stone wall in late game

[ShuiMienLung]

If you set up the wall so that something is completely blocked in, then enemy units will typically walk up and smack the wall to destroy it.

If you set up the wall such that you block the direct route to your armies BUT they could walk aaaallllllllllll the way around one side of the map to get to you, then usually they will do that rather than crush your wall.

This can:
give you several turns to put traps in their way (possibly killing them for medal advancement);
group them together letting you use Fireball or Fire Rain (possibly setting them on fire for medal advancement);
group them together letting you use Necromancer or Druid area attacks (possibly setting multiple negative effects on them lowering their morale and making them easier to kill);
group them together letting you use dragon abilities that have short range (possibly setting up multiple dragon uses, letting you use more rage for medal advancement);
cast Slow (guaranteed to slow one unit down) or Ice Snake (chance to Freeze [slow down] every unit hit) or Lightning (chance to Shock [slow down] every unit hit) to make them move even more slowly, letting you Do Other Things (like putting out two mana accelerators from the dragon every turn after you Awaken him);
funnel them into a single file letting you put One Big (spell-buffed) Unit out front playing Cuisinart (probably an always-retaliate unit like Griffin, Royal Griffin, Demon, Executioner, or Black Knight [after getting Moro's crystal])...

And so on. There are lots of possibilities. But again, the best use of the wall might not be as a *stopper* but rather as a *funneler*.