Tackling

Fish has been quoted as leaving tackling for that first ore-season game and usually the tackling is poor for the game and gets better in the next practice games. Wondering why. Isn't tackling a very important skill in football? Like in tackling, blocking, passing, running and kicking? If there are 5 skills why only practice four? I certainly get that we want to keep away from injury and the new rules limit contact, but, if I'm the HC we practice all those skills as many minutes and seconds as we've got. Seems weird to me that Fish was a db on the greatest most ferocious defenses ever in the '85 Bears and puts such emphasis on D that he would be all over tackling. Penetrating, wrapping up, driving back hard, finishing. (am I the only one getting warm right now?) In the past few seasons I've seen too much arm tackling, not enough wrapping up and finishing through the whistle. Opponents have run all over our D like the Skins last year.
Making personnel changed is important and there's some new guys back there, but doesn't coaching come into play as well? And I'm not talking about rushing techniques, spin moves, blitzing and all. Think he schemes are fine. It's just actually getting them to the ground. Why not work harder earlier on that?