Which years are you referring to?
Again, it is inaccurate to refer to Emmitt's dominant lines as if they performed to one elite standard his entire career.
That all-timer line existed for about 5 or 6 years out of Emmitt's 14 or so year career.
Just like the way people overrated the talent of the Cowboys of the late 2000's they overrated the talent of the 90's OLs.
Big E was dominant from 1991 to about half way through 1994. Larry Allen was dominant from late 1994 to the early 2000's. There were no other dominant players, just decent ones who keyed off of the play of one or the other of these two.
Mark Tuinei (1983-1997) went to two pro bowls, Nate Newton (1986-1998) went to six, and Mark Stepnoski (1989-1994) went to 5.
All of that was on the coattails of either Big E, Larry, or because of the popularity gained from playing in Dallas.
Those guys sucked ass before Big E arrived in 1991. I don't have any magic stats to demonstrate it and can only tell you how bad they were. Nate Newton in particular mostly made all-pro teams and probowls because he was grotesquely fat, popular, a Cowboy, had a nickname, was a great interview, and John Madden loved him.
The line gelled in 1991 when Big E found his stride and didn't look back until 1994 when he got hurt. Then Larry picked up the ball in late 1994, but the team lost Gesek and Gogan who were solid pros. They even let Ron Stone go and kept fat Nate, which really pissed me off.
When Ray Donaldson arrived in 1995 the starters were downright scary playing together as you had two dominant players keying all action from the inside out in Donaldson and Allen. After Ray got hurt against the Chiefs the OL was never the same. It all got old together and there was no depth.