The predictability of sims can provide a service by acting as a good "control" group for any experiments or changes that you want to test with your team.
Some sims have fairly decent rosters, look to schedule them for better tests.
Anything that will help your team play more efficiently or effectively overall should help you vs. sims and humans.
That said if you want to make deep playoff runs and compete for titles then you'll get more useful data vs. the better human-coached teams in your division, those games are going to give you the most big picture information about how your team stacks up when the games matter.