You're reading the right material to build your "traffic cop" structure. Based on the information you provided, I wonder if the customized timing you're trying to achieve could be done within the email itself so that your track segmentation could be built around something else. Let me elaborate:
Let's say you want your first email to say "Register by February 1, 2013" because that is 10 days after the lead was created. In SalesForce, you could create a custom lead/contact formula field that displays the date that is 10 days after the lead was created. Let's call that field "10 Day Deadline."
In your Marketo email, use a token to customize the content. "Dear {{Lead.First Name}}, Register by {{Lead.10 Day Deadline}} for this offer!"
All of your leads can go through one track regardless of the date they were created. The timing of the emails could be based on the length of time they've been in the track. For example: Send Email, Wait 3 Weeks, Send Email, Wait 1 Week, Send Email, Wait 1 Day, Send Email, Wait 1 Day, etc.
This way, you don't need to build a different track for each lead created time period. Instead, build the tracks around something else more relevant from the lead's perspective such as sales stage, title, industry, etc. Like this:
(Image adopted from Eric Hollebone's material)