This isn't about JO or Baby, it's about Doc's refusal to match up with Miami's small ball lineup.
When Miami goes small with Lebron at PF and Bosh at center, Doc should be using Jeff Green to matchup with Miami but he's not doing that. He's either playing JO or Baby, and that creates two bad matchups for Boston. 1st, it puts Baby or JO on Bosh, and neither guy can guard him. 2nd, it puts KG on James Jones, taking the Cs best interior defender and putting him out on an island 25 feet from the rim where his rebounding ability and help defense is much less effective.
JO can't play more than 20 minutes a night because he's virtually useless on offense and can't matchup with Bosh when Miami goes small. He's a great defensive matchup against Miami's traditional lineup, but when the Heat go small or we need to score more, he has to sit.
This isn't a Perk v. JO thread, but the sad reality is that JO is worse than Perk on offense. Both guys are limited physically, but Perk bests JO on offense because he simply knew the offense better, knew where to position his body to get open layups and dunks, and he knew how to set good picks. KG might be the best passing PF of his generation, but he has absolutely no feel for where JO is going to be on offense--and that's because JO has no idea what he's doing on offense.
So, no, it isn't about playing JO 5-7 more minutes, or limiting Baby's minutes, it's about matching up when Miami goes small, keeping KG on Bosh as much as possible (and keeping KG near the rim where he does his best work), putting Green on Jones and then using Green on offense to spread the court and get out in transition.
But Doc is a stubborn guy. He wants to impose his will on Miami and make them pay for going small. Sadly, neither Baby or JO can make them pay on the offensive end, and I've already explained how they get exploited on the defensive end. Doc's only real option to crush Miami's small ball lineup is Shaq. Outside of that, he MUST use Jeff Green at PF or Miami will continue to use their small ball lineup at the end of quarters. Last night they went on a 13-6 run in the last 3 minutes of the 2nd quarter precisely because they went small and the Cs didn't match up. That's on Doc.