When SNS and SNSK pins are connected to the same port, different pins can be used as SNS and SNSK pins.But SNS and SNSK pins are configured with few rules keeping in mind as illustrated in section
Pins A0 ,A3 and A5 of PORT A are SNS pins and pins A2,A4,A7 are SNSK pins of PORT A.
Channel 0 will be forming a SNS-SNSK pair as A0A2.
Channel 1 will be forming a SNS-SNSK pair as A3A4
Channel 2 will be forming a SNS-SNSK pair as A5A7.
The channel numbering is not dependent on the pin numbering.