If you do chest and shoulders on different days, then have a leg day or rest day between them.
I like workouts that pair opposing exercises so there is no wasted time between sets. You can do that with chest and shoulders:
Bench press & rear shoulder; Overhead press & upper chest cable; Dip & mid shoulder
Arnold did chest and back together in the AM. He would then do legs the same day PM, But later conceded that it would be okay to wait until the next day to do legs. On the following day he would pair front and rear shoulders and then biceps and triceps.
I'm currently trying to make arm gains with the following split of all paired exercises:
1)Leg&Forearm: DeadLift/StandingCalf, HipThrust/SeatedCalf, LegCurl/WristCurl
2)Chest&Arms: BenchPress/BbCurl, Dip/BlasterCurl, UpperChestCbl/TricepsPushDown
3)Calf&Forearm: StandingCalf/WristCurl, SeatedCalf/WristExtension
4)Back&Arms: WeightedPullUp/ SkullChrusher, BentOverBbRow/KickBack, Pullover/CblCurls
5)Leg&Forearm: Squat/StandingCalf, Lunge/SeatedCalf, QuadExtensionMach/WristCurl
6)Delt&Arms: OverheadBbPress/DbCurl, SeatedRow/TricepsOverHeadDb, MidDeltDbRaise