I just build two tiers, tier one is web 2.0, and expired domains hosted on different hostings (a sort of blognetwork but different)
Tier two is full blasting (5/10K links a day per tier one property), i have done a lot of testing since i have GSA and i haven't seen any benefit in more them two tiers and yes sometimes my tier one gets de-indexed/de-ranked and i lose a view rankings so now and then, but i haven't lost a moneysite or huge rankings with my method
After a lot of testing i have concluded that all these complicated link methods you can find on the internet work because of the first two tiers, the rest of your tiers are a waste of juice, time, money and recourses. build your tier one slowly and then blast the shit out of your tier one
Good luck.