The hard reset is not aggressive. YOur phone collects a lot of stuff and memory creeps. I used to hard reset my phone every time I updated the firmware. It is lik buying a new phone because the phone gets quicker and every thing works better afterwards. Just like the first day you had the phone.
Possible alternative is to download one of the file managers from the Store and try deleting the files one by one. I used to use one I think it is Y browser. Make sure you know which files to delete.
Yes, i do understand. My recommendation is to hard reset to remove any traces of a bad install plus any other bloat the phone may have accumulated over the years.
If you want to try deleting the files manually yourself and you know which files to delete and where they are then you can try the phone browser as I suggested earlier. I am sure you are aware of the consequences of deleting the wrong file.
