The Colonial Fleet BEFORE Cimtar
It makes absolutely no sense to assume that the Colonies entire defense was oriented around twelve Battlestars. (There is in fact nothing to indicate that there were only twelve Battlestars. That belief came about later in Fan Fiction.)
There were other types of military vessels. Commander Kronus, the retired Commander of the Battlestar Rycon and former Commander of the 4th Fleet, mentions in the series that the 4th Fleet consisted of 600 vessels. It is unlikely that these are all Battlestars! Information in the novels and other sources, refer to a variety of ship types, patrol ships, destroyers, escort destroyers, light cruisers, cruisers, light carriers, heavy carriers, Gunstars and Missilestars, to name a few. The Colonial Military had a variety of problems other then the Cylons. Piracy was an ever present issue, and it was the prime reason that the Colonial Military was formed in the first place. Colonial space covered a vast area and it was essential to maintain a presence in many places at once, thus a large array of lighter fleet elements.
The bulk of these light Fleet elements were lost in two critical battles that occurred prior to the Massacre at Cimtar. First is the Battle of Cosmara Archipelago, in which the Battlestar Rycon and the bulk of the 4th Fleet were destroyed. Second is the Battle of Molecay, where the entire 5th Fleet, including almost all the remaining Light elements, were lost, as was presumed the Battlestar Pegasus. Obviously some light elements survived the fall of the Colonies. Some would be out on patrol, escorting convoys or guarding distant stations. The Galactica, as the only Heavy Element remaining, became the locus of regrouping. Signals sent on the military frequencies would have summoned the remaining ships, they would have escorted in civilian shipping as it was encountered. Coming from distant parts and taking long, circuitous routes to avoid detection, meant that the Fugitive Fleet would continue picking up new members long after the initial flight.
IF the Pegasus survived the final confrontation with three Baseships, it is possible that it too would have picked up a number of survivors and stragglers.
What is a Warrior?
To the public eye, everyone in the Colonial Military is a Warrior. The reality is somewhat different. The Warriors are in fact the fighting arm of the military, the ‘sharp end’ of the stick as it were. The bulk of military personnel are Technicians or ‘Techs.’ This classification covers Medical personnel, Engineering and Support groups. Some Techs are ALSO Warriors, but most are not (This is especially true for Med Techs who are battlefield medics and those Engineers who operate at the front.)
Warriors and Technicians all use the same rank system. A Captain in Engineering out ranks a Lieutenant who is a Viper pilot. However, the engineer would not try and tell a Viper pilot how to fly, nor would the Viper pilot try and tell an engineering tech how to fix the life support system.
Though the archetypical image of a Warrior is a Viper pilot, not all Warriors are Viper pilots, very few have the qualities needed to be a pilot of any kind. Most Warriors are (were) part of the Colonial Planetary Forces. These Warriors do most of their fighting on a planet surface (though there are elite groups used in boarding and ship to ship assaults.)
Viper Pilots are part of the Colonial Space Forces (CSF) the fleet that defended the Colonies from Cylons, pirates and other off world threats.