If u are on a 3 days schedule, advise u to split up the work to push pull leg or upper and lower days

and DB chest press is not isolation, its a compound exercise

per session u doing 4 big compound exercises

if u do it correctly, u wont even have any energy left to do 2 bicep 2 tricep exercise

if u do, means u are leaving reps out the tank for the first few compound movements

can group leg, bicep and core to a separate day