For most cases in contract recruiting you will commonly see professionals that have spent a large portion of their career working temporary assignments. In these situations, job hopping is less of a red flag but can, in some situations, still be applicable.
While short job transitions should raise the flag, it’s the reason of why, that should concern you. Consistently hearing that a candidate left multiple positions within a short amount of time due to money, bad bosses, or poor work environment are all signs that you may want to reconsider representing them.