Verified answer

As you stated, pharynx is the back portion of the neck.

A phalanx is the war strategy that was used by the Spartans. The idea of the phalanx was to have a row of shields which would be used to take the brunt of the enemy's charge. Then, the Spartans would use the shields to move the enemy back and then they would kill those individuals that fell as the row of shields advanced into the on-coming attackers.

So I do not think that anyone would confuse a Pharynx with a Phalanx.

You might get a better response if you post this in the history category or military category.