This might actually not be bad for its size, considering it is 1080p and this series is harsher to encode than others. You could have saved space doing Ordered Chapters, also this aired at 720p, so it is just an upscale and you could have saved some space there. May as well shamelessly do some self promotion here: https://hi10anime.com/archives/82395 Great website for x265 releases + we use OC and the release also includes GJM subs, that despite their slowness in updating (understandable for the series), is very much worth it vs CR/aniplex subs, alot of dialoge changed for the better.

If it is 720p only why does horriblesubs have 1080p uploads?

Crunchyroll and other sources upload 1080p because higher bitrate. It's not a noticeable difference and only in heavy bitrate scenes like action does the 1080p uploads actually matter.

i'll keep that in mind how can you find out what it originally aired at?

Generally speaking, anime is aired at 720p most of the time. If you see 1080p those are just upscales but not their native res.

Thanks for this! Great job!