I’ve worked at a place that both collaborated with IDEO at certain points, and did “clean up” on their work for our clients later, to get into production. This was ten years ago. Our firm was a reputable resource for product development. Weak on ID, strategy non existent. We were not ‘Tier 1’. It’s a general term for typically old school firms that have expanded and usually define the furthest reach of the ID world into the business world, at that time. Continuum is another.