Top 10 doesn't say that much. If half your keywords are stuck fluctuating between 9-10, then you won't get much traffic. Tthey can, however, claim that they have delivered. There are a loads of other positions to consider. Position zero, "People also ask", images, videos, whatnot, all taking up valuable screen real estate on the first page, seriously deminshing the value of position 5 to 10. Hell sometimes even position 2 and 3. I'll join the chorus by saying you shouldn't hire based on promises. Not a specific one and definitely not one so vague. Top 10 is rarely difficult, even on quite competitive queries.