The one I'm talking about is a tactic I've seen on youtube and later fully optimized it for my own usage (optimal physical position of the phalanxes, optimal angle to keep them, etc.)


If you're not familiar with it, it kind of remembles this :
iiiii
\i/
Where "i" represents walkable areas, and the slashes represents where the phalanxes are places - basically you use them at chokepoints like bridges and gateways/wall breaches.

The enemy that walks in gets almost instantly killed because they are getting stabbed from 2 directions at the same time, and the "vertex" of the formation is virtually unbreakable because the pikes are crossed and there is virtually nothing but pike points in that area.

It's been really effective, you can use it with any units that are able to phalanx. It does get broken however...due to a couple of reasons
1) enemy missle units that fire up on your now exposed flanks
2) medium amounts of bodyguard cav/cataphract level cavs are able to push past the pike points and can stay significantly longer than any infantry.
3) the enemy sometimes DOES flank you by crossing at another location (it even happened to me once in a bridge battle, I was so impressed i gave them the victory)

I was undecided whether this was actually an exploit or just a good formation to use in bridge/city battles, because I have a hard time believing that V-formations werent used in history by significantly outnumbered defenders of narrow chokepoints like thermopylae, city walls, or other areas - with proper flank and missle fire, it is unbreakable.