Now that I have been playing HD again for 4 seasons I have been having difficulties finding the right balance for scheduling non-conference games. I prefer to play human opponents however with the game populated by far fewer humans than when I started playing I am having difficulties finding the right balance of NC games. I find that my SOS gets too high I am playing half of my games vs ranked teams because there are not enough middle of the road human teams. This results in more non-conference losses than I would like and makes it more difficult to make the NT.
How do others strike a balance of playing against 8-10 humans in NC and winning enough games to have a respectable RPI?

This is well thought out and well written. I'm not D3 so I don't really want to comment. But I will anyways.

One thing you can do if it's strictly numbers based desires, play10 sims on the road. Sort by Jrs and see which sims have big senior classes coming up next season. If your team is capable of beating sims, you can go 10-0 and turn out ok. Road wins are worth more than home wins.

Or try scheduling just 5 humans and 5 sims on the road. Shoot for road games against those humans.

Maybe look around the conference's in that world. And find other coaches that are in all sim conferences and will likely win 20 games. Play them, and hope to win.

Avoid teams in conferences full of humans that are good, but will finish in the bottom of their conference (due to all elite coaches being there and beating them). Avoid home games with sims. Avoid any sure loss, if you're not top 10 don't play against top 10 teams.

If you think you're a top 30 team, aim for multiple teams that may finish 40-80. All random ideas that you can consider. Hopefully others chip in

If you prefer not to schedule against Sims on the road like Top mentioned, of course you’re more likely to win games against human coaches at home.

If you want to schedule 8 to 10 human-coached teams, you’ll need to spend more time projecting how good they’ll be. I’d wait until you can see your RPI during conference games, and judge where your team RPI will be the following season. Then when you’re looking for teams to schedule, look at the current RPI and the roster to see how many players that team loses.

If you want to schedule 10 humans and you want 10 wins, find teams you project will not be as good as your RPI. Then... your odds of winning are better at home.

As for SOS, quality Sim opponents as away games might be better. But if you’re set on playing humans, you’ll have to take a deeper look at each team you schedule.