You can build any amount of tiers you want. The question is: what are you looking for?
In fact there are certain SEO strategies, where people build a huge link pyramid with tier 5 and tier 6 interlinking with the intetion of highly impacting certain amount of powerful MS.
Example:
Imagine you build 256 sites, with very very easy ranking long tail keywords. This 256 sites receive 0 incoming links, and they easily rank by themselves. They start receiving visits, and somehow, they even get linked by external sites, because they are good by themselves, you cuould even send some extra 2.0 links to this 256 sites, which represent a TIER 4 linking phase. Lets say they can achieve a 10/100 reputation level.
From this 256 sites, you send 4 link to 64 other sites. This 64 sites will receive the "power" of this 10/100 sites for a relatively more difficult ranking keywords, but with a lot more visits. Similarly to the first deeper tier, you will get even more reputation, lets say a 20/100 reputation level.
Then you send 4 links from this 64 sites, to 16 other sites with difficult ranking keywords. They will be ranking and having a very good amount of visits, and their reputation will go very high, lets say 30/100 reputation
Finally you send 4 links from this 16 sites, to 4 sites which are you money sites with very difficult ranking keywords but a ton of visits involved, for a 40/100 reputation, which is a high status overall.
So here is the schema for your 340 site network:
MS = 4 sites
Tier 1 = 16 sites
Tier 2 = 64 sites
Tier 3 = 256 sites
Tier 4 = 2.0 and other properties that go to Tier 3.
The problem of this, as you may observe, is that the amount of time involved here generally is huge. Also, unless you use a very random algorithm to avoid a clear interlinking and a huge footprint, Google may easily detect this massive blog network, and reduce the power a high %. This is why a lot of people, including just skip so much hassle, and cut down 1 or 2 tiers, with a lot less amount of sites, and a relatively similar amount of interlinking to get, more or less the same results
This is why, many people like @
tiiberius will not recommend going further than a tier 2, being the tier 2 the worst tier with the biggest amount of shitty and poorest quality of links, and the tier 1 with quality and mostly PBN, guest posts or refined 2.0 properties.
But don't forget that pyramid schemas required more tiering if you want to profit from a scalonated reputation strategy. You could simply put 336 sites linking to your 4 money sites. But overall those 336 sites will be mediocre at best without being able to drive any visits at all (since 64+16=80 pages will have too harsh keywords, to be ranking at all)
