Think Truk was a Navy base, little Army input. Japanese had two distinct armed forces, each with their own Air Force, Ships and Troops. Army battles tended to have Army troops, support ships and aircraft.
The majority of aircraft at Truk were Navy. Not sure if there were any Army Aircraft there, they sometimes got involved in primarily Navy battles (Rabaul was one) but on the whole, the Naval Air Units fought over their operations while the Army Air Forces fought over Army Operations.
In short, majority were variations of the A6M.