Published File Size, Extra Videos, Compression Best Practices

Hi,

We've been building some products in Storyline and have encountered issues with the overall file size of the published scorm package, with video files taking up the majority of the space (something like 720MB of 750MB file). Looking in the media library, it seems that the existing videos should only account for something like 330MB. The developer helping with uploading to the LMS has found that there are 4 extra videos in the scorm file that are unaccounted for in the media library, which is contributing to the size issue but can't be the only thing afoot here. 

With all of this, I've got a few questions - first, what might be causing the ballooning of the overall file size? Second, where might those ghost videos be hiding/deletable? Third, what's the best way to treat the video files so they're not taking up as much space? We ran them through Adobe Media encoder to reduce the size originally, but does that initial compression cause any issues with the auto compression that Storyline's doing behind the scenes?  

If anyone can offer some help here, that'd be tremendous.