I know this has taken a few days, but wanted to think this out.
Not all teams run on first and/or run on 1st and 2nd downs. If a team decides to pass on 1st down or 2nd and short, Thomas becomes a liability. He will get away with only pass rushing on pass downs for a short time. Teams will start looking for him and put a RB or TE to help block him.
I have seen Hali and Houston drop into coverage. Not both at the same time, but one or the other, unless in hybrid defense (4-3). Do not know much about Ford, but will look.
Thomas will not hold up at NT or either DE or 5 tech DT, if he does not add some weight. So, if he used used like that then add the weight and play there.
Remember, this is not College any more. What he did in college, might not transfer to the pros (see Werner).