Why would the legal issues be any different? I would think the laws would be very similar in putting people in video games, regaurdless of the sport. I guess it could have something to do with a difference in players union policies???
Answered your own question.

That is to say, that's the impression I'm under, that there are certain small technicalities that differ between the two leagues and the respective unions and that game developers are differently handicapped (or face no roadblocks at all) when adding former players as a result.
Just like they did a few times with Jordan in NBA live, only i believe they even used his jersey number, correct?
Kind of. The ratings were there but he was called "Roster Player" and wore a jersey number in the 80s or 90s. NBA Live 97 was the closest to using his real stats and so forth though. It had two Roster Players, one representing Michael Jordan and the other Charles Barkley. Strangley, the Bulls' Roster Player wore #24, was drafted 4th overall in 1985 and was born in Queens, NY. The Rockets' Roster Player was drafted 6th overall in 1985, wore #3 and was born in Mobile, AL. Or something like that. Their bio data was very close to be accurate, save for a couple of details (almost always one higher/lower for the year/draft position etc).