This isnt a glitch. 3-4 teams use 4 linebackers when running the base 3-4 defense but when they go to nickel or dime, their base defense becomes a 3-3-5 or 3-2-6. Below is the complete rundown for all five default teams that run the 3-4 defense -
CHARGERS
Formation / OLB / ILB
3-4 / 2 / 2
Nickel / 2 / 1
Dime / 2 / 0
Bear (4-3) / 1 / 2
Goalline (5-3) / 2 / 1
Prevent / 1 / 0
PATRIOTS
Formation / OLB / ILB
3-4 / 2 / 2
Nickel / 2 / 1
Dime / 1 / 1
Bear (4-3) / 2 / 1
Goalline (5-3) / 2 / 1
Prevent / 1 / 0
RAVENS
Formation / OLB / ILB
3-4 / 2 / 2
Nickel / 1 / 2
Dime / 1 / 1
Bear (4-3) / 1 / 2
Goalline (6-2) / 1 / 1
Prevent / 1 / 0
STEELERS
Formation / OLB / ILB
3-4 / 2 / 2
Nickel / 2 / 1
Dime / 2 / 0
Bear (4-3) / 2 / 1
Goalline (5-3) / 2 / 1
Prevent / 1 / 0
TEXANS
Formation / OLB / ILB
3-4 / 2 / 2
Nickel / 2 / 1
Dime / 1 / 1
Bear (4-3) / 2 / 1
Goalline (5-3) / 2 / 1
Prevent / 1 / 0
That's the default rundown for all five teams that run the 3-4. A team like the Chargers or Steelers will have their OLB's get more stats because they're featured more than the ILB's but the Ravens are the opposite because their ILB's are featured more than their OLB's.
Also, if you want to get the higher rated player with more stats than the lower rated player, make sure that the higher rated player is on the left side. For example, the Ravens ILB Ray Lewis is on the right side. Switch him to the left side and I guarantee that he'll get more stats if he's healthy because he'll be in on more of the plays.
Hope this helps.