I think it depends on what your opinions of the linebackers in later rounds are compared to that of the corners. If you think the corners are better, you should maybe take Reddick and vice versa.
As it stands right now, if I had the choice, gimme Reddick. I think Lattimore is gonna be good but I see a ton of potential and upside in Reddick. He can be a cornerstone building block at linebacker with the right development.
You guys are too premature on him being too light..like he doesn't have plenty of time to bulk up plus not everyone has to be 250+ to be successful at olb..as long as he has some sort of speed and strength that's what you should pay attention to