If one goes through the Prasasti of RRC - and ignore Kandalur salai (for time being) then will easily realise the priority for RRC to chose the Provinces to be sub-dued..
Vengi Naadu : to protect his daughter and son-in-law from Satyachreyan Gangapadi - Nulambapadi : YES.. Origin points of Ponni river - Cauvery !! To ensure free flow of River Cauvery into the Chola heart land .. !! Of course - we are presently experiencing 1000 year old obstructions for Ponni river to reach her husband Samudra rajan !! Rettapadi - The Politicals alliance between the Krishna II & Krishna III with the Nolambas - and their evil designs to subdue Parantaka I (because he fought against his father Aditya's father-in-law ) who ascended the Chola throne in about 910 CE after Aditya's demise. Pls go through KAN Sastry's The Colas...
Painfully Sastry concludes : Mathirayium Eazhaum konda parakesari Parantaka I - in about 47 years of rule (910 - 957 CE) - lost all he gained and when he died the Chola empire was in shambles. Arinjaya - Sundara - Adithakarikala - Uthama could not match Krishna III 's evil design.
Though Sastry RIGHTLY refers to an inscription that Aditya karikalan engira Parthivendra varman, Kudanthai Sethuraman differs with him and shows several instances in same temples / same walls where Parantaka - Sundara - Aditha Karikala - parthivendravarma inscriptions are scribed !! Sethuraman states that Parthivendravarman met Krishna III in Melpadi - in about 965 CE or so.. Uthama came to power in about 970 CE or so... RRC came to power in 985 CE. RRC avenged the pain caused to his great grand father Parantaka and destroyed the Gangas, Nolambas and finally Rettapadi (Manyakedan Raichur) in 1006 CE. Imagine - Sathyachreyan also called himself Rajaraja !! that explains the fury behind the on slaught described in the Hattur inscriptions. Over these priorities - Kandaur salai - of course need not assume priority to figure in the destruction list. Most of the Historian draw reference to Udagai expedition and refer to " Keralandagan " title assumed by RRC.. this has no relevance to Kandalur episode
I think this covers certain interesting episodes in the life of RRC.