Vic, sometimes on National Rail Enquiries I get what you got, i.e. "two trains listed, both departing at the same time".
Example would be my recent trip to Wimbledon. Both entries start from Gillingham at 10:51, but one is "change once, at Woking, onto the Waterloo stopper", and the other is "carry on to Clapham Junction, change there, and come back out to Wimbledon on any one of umpteen suburban services". Both, I assume, are "permitted routes".
The difference in eventual arrival time at Wimbledon was 2 minutes apart! Coming back, it was either 17:06 change Clapham or 17:08 change Woking, both with the same eventual arrival time back in Dorset. No difference in price. I opted for the Woking change as Clapham Junction has about 14 platforms and involved too much scurrying about …
(As for the 17:06 and 17:08 - my blinking Croydon tram was held just outside the Wimbledon station tram platform, and I eventually arrived at 17:10 !!
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