If you just simulate games it doesn't use the full tactical engine so, while depending on your team it could be better or worse I guess it def will give you different outcomes so that's why we changed to requiring it in the Challenges. There wasn't a difference before 07's 2-d engine was introduced.
Anyhow I think there's no doubt you get better results in playing your players in the proper roles which can only happen if you do your lines/tactics yourself. You can learn more about who's clicking and what issues pro and con your team is facing on a game-to-game basis by watching the games I think so overall it leads to better chance of success. I do 'very fast' with 'extended highlights' and after a few games you learn to sense how games are going etc.
But one of the key strengths of the game is you
can approach it how you want to and within a bunch of levels within each main approach which is cool.
As for multiple GMs, yeah I usually end up with AHL second year and sometimes ECHL too if they have a team... but keep in mind you can take over and hire coaches, set lines and tactics etc. and set them to 'vacation' and just check in on them every now and then, just set the GM Options so they don't change your lines or hire a bunch of naff staff back when you give them back control
