Ultimately we want something that works clinically for what we are treating. There are some plants that work better fresh, but most plants will work dry. It can depend on what we are using it for also. One plant will work dry for a specific situation and need to be used fresh for another situation. I make tinctures from dry material if I can, as it is much easier to do, and yes, I can make it stronger as far as density of product.
One issue that comes up with dried herbal tinctures is how old the dried product is. Some herbs will be fine if we make a dry tincture out of them immediately after drying, but if we wait 6 months, a lot is lost in quality. Some herbs I find to be better made fresh but dry is ok, I just prefer them fresh. These are the tinctures I usually add both fresh and dry herb to.
If a product only works fresh clinically for me, fresh tincture is what I use and I don't bother to add dry to the tincture at all since the dry is worthless in my opinion in some cases. Even though it is more work to make a fresh tincture or fresh oil, I do when I need to. Ultimately, if I can dry the plant and use it as a tea, that is the form I like best and it is the least expensive for people. However, teas have issues some times too for a variety of reasons.
Fresh plants are different than dried, just as fresh food is different. Making a dinner from food that sat in the refrigerator for a week or food that has been dried first (getting older on the shelf all the time) makes a difference. It is shown that nutrients are lost in storage and during shipment of food for a variety of reasons. Same happens with herbs. So, fresh or freshly dried is going to be best for most herbs just as with food, but not all. The better you store them, the longer a dried herb will last before tincturing it too. Often you are depending on someone else to have taken good care of the dried herb, keeping it in a cool room and out of the sunlight etc. There is a lot of poor quality dried herb on the market and it is best to grow and dry/process your own herbs.
Plants do have energetic qualities. Ultimately we all share the one eternal flame as our source, but we each, including the herbs have our own special vibration that spirit gave us. It is this energetic quality that we attempt to harness in homeopathics , flower essences and some tincture makers attempt to capture as well. The energy of the maker is infused into the product also.
I don't just look at known active components. There are countless examples of herbs that have been released as products on the market where they were sold by their most active components, only later to be found to not work as there were other unknown constituents not in the product that were in the whole herb. We know so little about what it is about an herb that makes it work the way it does. We know even less about what we are. Ultimately, we all have to follow the path that works for us, gives us a life we find rewarding while on the path and gives us results that enrich our lives. Some people prefer eating packaged food, while others only want freshly prepared food. Some foods are better eaten fresh such as a sugar snap pea or carrot while other such as a cannellini bean or brown rice cook are great as a dried food that is cooked up later. Some herbs such as Arnica, St. John's wort, Pasque flower, Echinacea purpurea, Bugleweed are examples of herbs I usually use fresh. There are herbs such as Garlic that should only be used fresh if for killing pathogens but can be used dry for other things. Even the herbs I mentioned that I used fresh would have some applications where you can use them dry, but I mostly use them fresh, so that is how I make the tincture. With the Ech purp, I add dry in at the last maceration as dry is useful as long as made from freshly dried root and not old root. Ech. angustifolia by the way will last a long time on the shelf, unlike Ech. purp. If they are made appropriately as tincture they are both great as tincture, but if you use them both as 6 month old dried root to make the tincture he E. purp will not be as good as the E. ang. as the E. purp does not last on the shelf as well.
Plants will share information with us if we show you we worthy. That has happened very few times in my life, but it has happened and this is the most profound data you can get. So, if you really want to know how to best utilize a plant, ask the plant. Show you are worthy by spending time with them, get to know them. Take care of them. Open your heart. Be open to what they share no matter what it is. Be thankful.