@Mike1933 If they are your friends, they could just book at the normal rate and you simply reimburse them privately. I have a friend who is also a host and we do this when we come to visit each other. So we each get the review and ratings, and it ups the guest count for Superhost status, which doesn't really matter to her, as she gets lots of one and two nighter bookings year-round, whereas I'm in a market that tends to get 10 day-2 week bookings and is quite seasonal.
The difference in them booking at the normal price or a discounted rate would be that they might be charged a higher service fee- but not necessarily that big a difference, because Airbnb tends to up their service charge as a host discounts the rate.