Silo Structure; Will links from home page to a Sub-category or Post undermine silo seo advantage?

I have a question about the Silo structure that I was hoping someone might be able to help me. I am building a four tier silo site:

TIER 1 ... Home page
TIER 2 ... Categories
TIER 3 ... Sub-categories
TIER 4 ... Wordpress blog posts

I understand from Bruce Clay's explanation of the silo structure, TIER 4 pages boost the Google keyword ranking of the TIER 3 pages, and TIER 3 4 pages combined - boost the Google ranking of the TIER 2 pages.

However, will links to anything other than TIER 2 pages on the Home page, undermine the silo structure and it's SEO advantage?