Any tactic will have some kind of weakness as in real life or in football manager. This tactic works because in general you will out score most teams you play against. You still need good players though if you are in one of the top leagues around the world. You will still need to take some effort looking for the right players and making sure everyone is fit and happy. Every team I have tried this tacic with from Bury Town to Liverpool I have won pretty much everything. I am no expert at FM and thats why I use other peoples tactics and I normaly have to tweak them in some way but not with this tactic.
I will post again after I have had a decent amount of games and see if things improve.