I believe the h320 is an MTP device so it won't look at date modified to determine if it should resync.
Also, updating the tags doesn't necessarily update the files (or the tags in the files), it may just be updating the tag info in the MC database. To make sure the tags in the files are getting updated when you make tag changes, make sure Tools > Options > General > Importing & Tagging > "Update tags when file info changes" is turned on.
And finally, different things will happen depending on what tags get changed. For instance, if you change the Name, Artist or Album tag we may not be able to match the file in MC with the file on the device. If you change the Comment tag it really doesn't register as a change between the file in MC and the one on the device.
Are you connecting the h320 as a drive or is it MTP?
MC will only delete files that are in folders spawned off of the base path specified in settings. So, if the files are located in \Audio\Artist\Album\file.mp3 and the path is \Music\[Artist]\[Album]\ the files won;t get deleted.
If you can specify the types tag changes you made, we can look into it further.