Ishaq Williams, similar to Manti, has the ability to come in and play right away because he is physically developed/athletic enough to play his position. There are only a handful of players each year that you can say that about, but Ishaq Williams at OLB is one of them. The question is whether he can get enough reps to learn the position well enough that he can beat out vets... and that's anyone's guess.
Manti got more and more PT as the year went on as a frosh. With Ishaq being an EE, by next fall there is no telling whether he will be ready to compete for a starting spot, but it is a very real possibility. No matter what I would be shocked if he is not on the 2 deep. My personal prediction is that you will see Fleming as a starter at the CAT position with Ishaq backing him up and getting a few more snaps each game as the season goes on. The other scenario is that Shembo will back him up.
I think Filer will be the starter at DOG with a battle behind him between a lot of guys (maybe even Councell... but Councell is also a good RS candidate) for his backup. Filer ended up 3 deep at CAT after a short stint on the 1st team in pre-season practice... but then transitioned over to being Neal's backup at DOG later in the season after Brian Smith moved inside. Looking at the crop of athletes we have, I feel he will be the best fit to step in as a starter this season. There really isn't a lot of depth at this one particular position because the DOG takes a pretty unique skill set. You have to be able to play the pass and the run which means a unique blend of speed, agility and strength is required. Ben Councell, in due time, should dominate at this position. It's as if his skill set was invented for it. But until he is ready, Filer is very athletic and should be the starter there.