Hi 'R'
Wow - dry vrs fresh, that is a great debate on herbal forums: One of my fav discussions can be found here -
Henriettes Herb Forum
Long discussion made short, it depends on the herb and personal preference for the end result. No herbs are the same, each has its own characteristics. With the herbs you have listed and for the use you mention I don't see a problem with using dry. That said, you will want to make sure you use the right alcohol proof for your tincture when using dry herbs.
In your link, Gwen recommends
Rose Mountain Herbs as a source for herbs - On the RMH website they have a information laid out nicely. See RMH Tinctures and Extracts page here
Rose Mountain Herbs You may find this information interesting.
There is loss in herbs potency over time, some much more than others. Woody herbs and some roots dry and retain their potency better - generally speaking. Personally I've only used fresh roots thus far, but haven't read any issue with using dried second year burdock as long as it is harvested properly (in the spring).