You can define, for the search engine, more about the link structure in sitemap.xml as well as robots.txt to help it understand better to counter the cross-link confusion.
The reverse silo is a good trend also, where the blog post is the "top tier" and the money is the suggestion. Regular silos are still great too.
Silo-ing or Theming actually helps site visitors (you know, those people who will buy stuff from you) as much as it does help search rankings. But there is an important aspect of SEO that can be a factor for your rankings overall. That is called click through rate and the time spent on a site. If a user visits your site and then immediately clicks off or hits the back button, this can hurt your rankings, especially if it happens frequently. That tells search engines that the keywords / phrases you're ranking for aren't relevant to people. The search engines will make rank adjustments by lowering your rank. One way to counter this potential problem is to organize your site and make it easy to navigate through. Your theme structure should be similar to this:
Main Theme
General Theme:
- Sub Theme
- - Details
- Sub Theme 2
- - Details