I am very skeptical about the Kalabahra period. We dont have information more than one paragraph about Kalabahras in history. Whole Kalabahra period is speculation after speculation.
All we have is name of Kalabahra ruler. His coronation by Dikshithars. Pandyas claiming to have ended his rule.
There is no conclusive evidence till date to know what was extent of Kalabahras..who are they ?..where did they rule from - we have absolutely no details...
They period saw some extra ordinary increase in Didactic literature - giving us one logic solution that during this period Jainism and Bhuddism was at its zenith in Tamil Nadu.
Tamil Literature can be classified as
Sangam - ettuhokai pattupatu with exception of 3 late Sangam - thirumurugatrupadai, paripatal, kalithokai Medival - All didatic literature (naladiyar thirukkural inna narpathu iniyavai narpathu nanool...etc) silapthikaram Bakthi works of alwars and nayanmaras
Historical clasification Sangam kalabahra pallava- pandya Late cholas
Kalabahra period might over lap with Late sangam and Diadactic literature period. But Since we have no facts on kalabahra period we can say anything more than this.