I've added some details to your stats, because they are relevant. Also, the tackle stats do not show missed tackles or bad pass coverage, the latter being a weakness of Minter's. They do not show how much progress the runner makes after first contact with Minter, as K9 likes to joke about Minter being dragged 3 yards before the runner goes down.
It is difficult to compare if Mosley or Hightower would be improvements, but we will see Sio Moore side by side with Minter and that should give us a good look at comparing him to another actual linebacker in the same defense rather than comparing him to Bucannon or the likes of Fua, G Martin or any other UDFA that have had as a backup the last two years.
Moore isn't really that good either if he was we would of known by now. You can just go back to Dansby and Washington to see what really dynamic explosive linebackers can do in this defense