>>58015655
Checked my Cyan Beach team, and if I were to neutralise my Suicune's nature the effect would be negligible. Suicune gets slightly worse whilst the team gains get slightly better.
Probably a waste of a neutral mint, it'd take a skill chance up mint to justify it.
Or it could just be that helping speed natures have a better effect on skill specialists with comparatively low skill trigger rates, for the special ones like Helper Boost.