Does anyone think that Cameron /Campbell are interchangeable ?
It looks highly unlikely to me.
Cameron is either from the places of similar names in the Lowlands, or from Gaelic 'cam' meaning 'crooked' or 'bent' plus 'sron' meaning 'nose' - a reference to a hooked nose said to be prevalent among descendants of the Highland clan.
Campbell is from 'cam' as before and 'beul' meaning 'mouth', so means 'crooked mouth', though the jury is out as to whether this is a reference to a physical or a moral characteristic.
Either way, Camerons and Campbells were on opposing sides during the Jacobite Risings, and it's hard to imagine anyone deliberately using them interchangeably, or even getting them mixed up.
But almost anything is possible.