A proposition to fix sieging tier 2 towers

My girlfriend had a great solution to the problem Hai brought up today in his interview of the lack of things to do after a team takes outer turrets. A cool solution rather than nerfing the shields or damage etc. would be to make it so the shields given by the tier 2 turrets would only be given if an outer turret still stood. So if a team was to take the three outer turrets the inner turrets would become easier to siege. This also makes it important to try to keep an outer turret standing. Some variance of this could help the stalemate that develops after the outer turrets go down.