2626 is overtaken by SBC ERS ICE which is a priority train and is a scheduled overtake and the rest of all overtakes you mentioned are rather unscheduled because of late running of any pairs of trains
The only scheduled overtake for Delhi bound Kerala is by MAS & SC RAJDHANIs & DURONTOs & Chennai Delhi GARIB RATH and scheduled overtake for Trivandrum bound Kerala is SBC ERS InterCity.
No other overtakes are scheduled.