[Phalanxes] What am I doing wrong?

[QuintusSertorius]

For some reason, I've always found, that if your line is longer than the enemies line, you'll get absolutely decimated. It's not something I've tested, but I'm always using my guys in a somewhat dense formation when fighting other phalanxes. That's been working for me...

I'm wondering if this is the case too; I leave them a lot wider than they are deep (the default they appear on the battle deployment) for maximum frontage. What I worry about is leaving gaps between them where the enemy can filter in and threaten their morale ("Concerned about exposed flank").