My ideal 2nd unit wouldn't be littered with inexperienced NBA youth, many of which have never played a second in the NBA. So for this year, I don't have an ideal 2nd unit.
I get where you're coming from on that, but I don't think it's so bad.
Kemba, Jaylen, Tatum, and Hayward should hopefully all be able to play 30-32+ mpg.
Smart is also going to get a lot of minutes, probably 28-30. That's going to cover most of the backup guard minutes.
Kanter is going to probably play 20-24 mpg or so. He may play more than that. Earlier in his career he averaged 26-28 mpg.
There are some significant minutes to fill at the 5. However, Daniel Theis is an established player with a solid amount of experience between overseas play and a couple years in the NBA. Poirier has 0 NBA experience, but he's 25 years old and has been playing professionally overseas since 2013.
Beyond that, we're talking about splitting up 30-35 minutes at wing / forward among all of the remaining bench guys (Semi / Langford / Edwards / Grant).
It's not an ideal scenario, to be sure, but they're not set up to have to rely on any of those unproven guys for really big minutes or a major role, unless the team is hit with big injuries.