Again, what year is this?
DTs who "keep LBs clean" are not valuable and rarely exist in the NFL anyway because you have to be mobile and big to eat doubles. OL are athletic and can easily seal guys who can't move. The flip side is that, if you have LBs who need to be kept clean, then you do not have good LBs.
Plus, smart teams run when they have numbers advantages - i.e. 7 blockers to 6 defenders. It doesn't matter if a DT eats a double team, because there's still a man to block every defender.
This is one of my favorite plays. Derrick Brown wins his gap but is sealed by Terrence Steele, and Luepke comes through the B gap leaving 4 blockers on 4 defenders on the left side of the OL. Biadasz/Martin have trouble and Biadasz struggles to get second level, but it doesn't matter, because the the LB (54, Green) now has to defend multiple gaps. The DL almost all win and it doesn't matter because they are outschemed.
https://www.dallascowboys.com/video/tony-pollard-scores-td-with-last-second-extension
Point being - players like Brown don't matter, because you can just run away from them. 54 has no chance, because they do not have enough bodies in the box as the high safety has to account for CD on the bottom. The counter to this is to have penetrating pressure players who can force a quick throw against press or a disguised so that you can put numbers in the box. Brown, or DTs who "keep LBs clean" can't do that.