Hooker and Mack have not regressed. Every rookie is being examined weekly and their tendencies are being studied to take away their strengths. Look at Ajayi last year. A few good games, and then mostly shut down. It happens. Mack has some skills that cannot be contained, the coach just needs to get him in situations that exploit those skills.
I remain concerned about Mack and his running style. He's not a stout build and he runs upright. Those two qualities expose him to injury. He's got to lower his pad levels to stay healthy.
The O-line has been bad for the Luck's entire career, we tried doing nothing this past off season and things have only gotten worse, not better.
However I agree about the ILBs! I'm not sure that they'll have to be first round picks, but we need multiple new players on our roster there.