In a medium bowl, combine olive oil, soy sauce, balsamic vinegar, orange juice, lime juice, garlic, cilantro, ground chipotle, ground onion, and ground cumin.
Carefully rub the Mexican oregano between your hands to break it down, avoiding the stems, then add it to the bowl and whisk everything together until well blended. The soy sauce provides enough saltiness, but add salt if desired and mix well.
Dip each steak into the marinade, turning to coat evenly. Place the steaks in a non-reactive container, preferably glass.
Pour any remaining marinade over the meat, spreading it evenly. Cover tightly and refrigerate for at least 1 hour.