I've got no idea to be honest.
One of the problems with using certain plug-ins is that I can't exclude unused files, because it winds up skipping a bunch of the animations and botching the deployment. I might be able to manually remove some default assets, but even removing placeholders that I don't need anymore can cause problems. I also do need a few default sprites in tact for the mercs, since actors need overworld sprites even if you can't see them.
In any case, I'll have to find a solid way of cutting down the file size eventually. Next update won't be much larger, but I can't say how big it'll be once all the first level Sins have their assets.