I found a very interesting document outlining the answer and I thought it's way too important of a resource not to share it
Prior to 1000 B.C. armies were organized according to
specific social structures. The nobles and members of the
royal family rode in chariots. The cavalry was composed of
lesser nobles and the infantry was made up of men from the
poorest social classes. There was very little organization
and no prearranged campaigns; battles were conducted
similar to a modern day raid.
TTR in these armies was very low as nobles were expected to supply themselves and peasants were expected to live off the land.
Early military societies
Around 700 B.C., war became the main business of many
nations. The need for increasing wealth was satisfied
mainly through the proceeds of armed combat. Military and
political organizations began to consolidate and blend.
Regular armies were created and the states, including their
financial and administrative systems, were built around
those armies. This military nature of the state extended
well into the Roman Republic and even to the feudal era in
the years 800 to 1000 A.D. A combination of civil and
military authority on the general’s staff facilitated the
administration and the logistics support of the armies.
Xerxes army is taken as an example. It is estimated that the size of the army was of 5 million and the fighting forces were around 150 thousand to 180 thousand. Even reducing the full figure by two-thirds (as contemporary writers were known for exaggerating numbers), TTR was around 9 to 1 (9 followers/supporters to 1 fighter).
The Macedonian army
The Macedonian Army between the years 350 to 320 B.C.
was probably the best military force known to humanity up
to that point and maybe even up to the 15th century when
gunpowder weapons were introduced. For the first time in
history, scientific analysis was used to design tactics and
battle movements. Philip of Macedon developed the most
thorough administrative and logistics system known and his
son Alexander was the first to devise and use prototypes of
field artillery that could be carried by mule or horse to
It is believed that the success of Alexander’s sustained military expeditions reflected in large part his careful logistics planning.
A study argues that the Macedonian Army employed one servant for every ten infantrymen and one for every cavalryman. Taking into account the infantry-cavalry ratio, as well as guards employed to protect camps, TTR results in an impressive 1 to 1.12 (100 followers for every 112 soldiers)
The Roman military system was based on an essentially
professional citizen army. The Roman armies were
successful because they introduced a new organization based
upon age and experience rather than wealth or social
condition. Rome traditionally had two consular armies,
each consisting of 18,000 to 20,000 men. Each consular
army was formed by two Roman and two allied legions, but in
times of war there might have been more than the 8 standard
legions. By 220 B.C. the total military manpower of Rome
was calculated to be 750,000 men.
If the figures are to be believed, it would suggest that out of the 750,000 men about 710,000 were support personnel. Yielding a rough TTR estimate of 18 to 1. If garrison forces are excluded, the TTR lowers to about 10 to 1. Comparable to that of Xerxes but much higher than that of the Macedonian army.
While figures to determine TTR in this era seem hard to come by, the french implemented in the 15th century the "Lance" system in order to support their troops.
consisted of a gendarme, a squire, 2 archers, and 2 pages
or valets who served as foragers, scouts and pickets and
were not counted as combatants
Resulting in a TTR of 1 to 2. Of course, when lances were grouped into big armies, it's very likely that the ratio increased.
Source: "An analysis of the tail to tooth ratio as a measure of operational readiness and military expenditure efficiency" by Tamara L. Campbell & Carlos H. Velasco