Completely agree. The last time I played a rom with 4-3 defenses was a few years ago and I thought it was heavily flawed from a blocking scheme standpoint -- too many holes to exploit -- and if that's what's causing problems with the TB.org rom, then removing that hack seems like a reasonable solution.
The LOLB plays closer to the line of scrimmage than his counterpart on the other side (ROLB), so when translating a real-life 4-3 to the Tecmo 3-4, I assign positions like this:
DE = LOLB
DT = LE
DT = NT
DE = RE
weakside LB = ROLB
middle LB = RILB
strongside LB = LILB
Most NFL 4-3 defenses employ a hybrid defensive end/rush LB type, so that makes it easy when deciding which DE to slide to LOLB.
Also, vs. the 1back set (far more common than the 2back set, at least in my rom), the weakside LB will have nobody lined up across from him on the line of scrimmage, which is the way it should be. The LOLB (real-life DE in the 4-3) WILL face a blocker at the line, so that works too.