Congrats on the tiny mulit-bar- They are neat fish. Very mellow, shy, and finicky eaters. I hope your tank is mature with lots of food for it to forage for.
Yes, Hawkfish will eat small fish. But it eat them whole. Things like eviota gobies, Green bar gobies, blue stripe goby, gold stripe goby - Long skinny fish it can gulp down it will eat.
But your multi-bar should be much more than a mouthful. And you should be fine!
Pending the size of your tank, if you have room, and can source a similar sized Multi-bar. In my experience with them, they easily pair up with others. I have not ever had success in keeping them in 3,5,6 together. But in twos they get along fine, and are a joy to watch picking across the rock work together. I always likes the Multi-bar beause to me it was the Poor-Man's peppermint angel.
Good Luck with your new baby.
Dave B