I think you're giving Allstate leadership to much credit for planning and, well, basic competence.
IMO, the NG purchase was opportunistic: big A had cash on hand and was bleeding market share. Fairly common to "impulse buy" like that. I don't think they had/have a longer term plan for integrating IA/non-standard business. They certainly don't have a record of success there.
I think they'll flail about with it for 2 or 3 years, maybe longer. Then they'll roll what's left of the business into their TG book and lay off many more people. Basically, they'll take the stock price bump for their "decisive action" and then mismanage the business into a slow death (a la esurance). By then they'll have some new shiny plan for domination, which will be equally deluded and ineffective.
TL;DR Allstate senior mismanagement is driving big A into the ground, but it will take years because they're so big.