[guncannon109]

This whole issue can be explained away with one simple over looked inclusion. In Abarenger they had an unofficial fifth ranger in the form of Abara Pink that was never included in the adaptation of Dino Thunder who showed up way before Killer as a comic relief character. With Pink that brings the total Abarengers (which is taken into account in Gokaiger) to six. The reason why Chopper is widely counted as five instead of six is the simple fact that Gekiranger only ever had five members and not the unofficial extra that Abarenger did.