my monday routine consists of chest triceps 3sets of 8 on each exercise failing on 3rd set

flat bench
incline bench
flies

closegrip bench
tricep pulldowns (cable)
and skullcrushers

finish

to be honest i have never did decline bench
should i be doing this , if i add it will it make my chest overtrained that day ?
slightly confused with this
was thinking maybe alternating it with flies 1 week decline next ?