The L-1 is a fine instrument for multinationals moving their own people. Its prerequisites are exactly what most growing companies don't have.
The person you want has never worked for you abroad — you found them in a paper, a repository, a competition. There is nothing to transfer; there is a record to engage. That is the O-1's shape: the case rides on their evidence, the petition rides on an authorized agent, and your company's part is one page.
Run the comparison per person: existing employee, year served, moving permanently into a U.S. role → L-1 is natural. New talent, stellar record, possibly serving several engagements → agent-based O-1. Talk it through with the specifics.