I do not know of any bracket coverage that is zone underneath and man over the top. To shake Gronk free, all you would need to do is send the TE and another receiver into the short zone and wait for the LB to react. Or you can send Gronk across the formation, away from the safety help and throw in front of the other safety. How that would be an effective double while accounting for other receivers is unclear. Maybe I am simply unaware of this strategy but the brackets I know are under/over or inside/outside and both are man coverage.
As for Hawk/Jones being off the field in the 3-3 you saw:
See #50. That uni is AJ Hawk.