The English patch + Japanese dub contains multiple audio files for Catherine's extra Voice DLC for it's FMV which makes the size big. 957MB modded files just for FMV's
The English patch + English dub does not contain those multiple for Catherine's extra Voice DLC making the English dub FMV size small (390MB for FMV), but the English dub also has modded English files (.acb/.awb) on the sound folder (430MB).
It's kinda just a coincidence that the size is closely the same lols.
if you want to save space you can safely delete these files listed on this excel sheet
https://drive.google.com/open?id=19GvljHzv1ujAN-_xsnNgwP-TpKjLjvr3
you can save almost 1.9GB