IR should go for HOG (Head-on generation). Both EMDs as well as 3-phase locos are 100% fit for providing electricity for the train.
As far as SG is concerned, it'll be better to eliminate it. SG has a lot of disadvantages :-
1. Maintenance of batteries
2. Presence of large dynamos and batteries increases weight of the coaches.
3....
more... More weight means more fuel consumption/ power consumption by the locomotives.
This is why IR is switching to EOG.
I hope IR switches to HOG soon. It's pollution free and efficient.