Given the mandate of the APs and regular force, I dont think there is any duplication of any kind in buying the chopper. The borders are mainly manned by the APs and work in those harsh and remote areas while regular force mainly maintain peace inside the country.
Unless one want to politicise every issue, I do not think there is duplication of any kind. Just like The kenya Army has choppers while at the same time the Kenya Airforce has the mandate in the skies.The two units (KA & KAF) do not duplicate roles.