Platoon system has it's positives and negatives. But I like it in the right situation.
1- Players (especially your best 2-3) have to BUY-IN totally.
2- Players have to go 100% while they are on the court, no taking plays off.
3- There can't be a big difference between your best 2-3 guys and your 8-10 guys, and not much difference at all between 4-5 & 6-10.
4- I think it works best if it is NOT a 50/50 split. Make it say 60/40 (or even 55/45). That way there is incentive for playing better/harder and getting on the 60 or 55 squad instead of on the 40 or 45 squad (8 or 4 more mpg).
5- Creates great chemistry, since you are playing w/ the same 4 guys all the time, you know where each other are, where they like to get the ball.
5- If done right, you simply wear the other team out. It worked great for us in 2014, UNTIL the Poythress injury. We were holding good teams to <30% shooting EVERY game. KU < 20% shooting. UCLA had like 8 pts at halftime. There was a little bit of dropoff w/ our 10th guy, and that injury put him at #9, and the new 10th guy had an even bigger dropoff, so Cal went with a 9-man "platoon" where the 9 would sort of rotate that as that 10th guy, so you had 1 guy not as fresh, and not consistently the same guys playing together, and then before long the platoon was gone.