Aren't they almost the same tune? Sounds like a fairly rudimentary little variation upon a theme to me. Film composers like Williams and Zimmer are often berated for stealing from Holst, but what of this?
There are a couple of similarities, but, save a regulation IV, V, I cadence, not really the same chord sequence.
I think the Williams / Holst thing stems purely from the the type & rhythmic nature of his chords used in the first scene in Star Wars, but I can't think of anywhere else. I'd even go so far to say that Williams is the better composer...
You can avoid your hearing similarities by listening to the infinitely superior Harold Darke version of In the Bleak...I've always found the Holst one rather dull.