Agree with Harv on ZayF, he's a good kid from what I've heard. Had to "bulk up" to 180 for the combine. He's 5'9" and when you're that size with 6' corners covering you, your QB is going to have a very tight window. Also, being that small means you're less likely to last 8-10 seasons.

As for Hyatt, the Will Fuller comp isn't far off. GB supposedly likes him, and at 6' with long arms he's a little wiry, but again he's 175-180. If you have him out there he's not going to block, but if you run him and Watson on 9 routes with Doubs and a good TE in there as well you could stress a defense. They have Bo Melton, Hyatt's like a better version of him.
I'd just press and mug the hell out of him until he proves he can beat it. I think he's very explosive but IDK about his agility.