I play in huge size only.

Historically, a Roman Marian Cohort would have a paper strength of 480 men. Formed 4 men deep, you would have 120 men to the side. Battle lines were very long and thin. A Marian legion would typically put 4 cohorts in the front line (almost 2,000 men) yet, this first line was almost four men deep.

The only way you can get close to representing this extremely long and thin lines is by sticking to huge unit sizes.