I started playing a Totem Druid lately. I really enjoy the possibilities of a Druid who is having one specific animal form (in the case of my PC Spider).
I just wanted to give some feedback on a few points I noticed as well as ideas that came to my mind concerning the optics of Totem Druids:
It seems that the Epic Dragon Knight Summon is not scaled up in size. It uses very tiny totem animal model compared to the totem polymorph form, animal companion and the elemental swarm summons. I would think this is something that was maybe just overlooked. In my eyes, Dragon Knight could apply a similar scale factor as the totem polymorph form at the end level (that one is really huge) to reflect its power.
In contrast, as mentioned, the totem form becomes really huge at end levels (depends on the base model, the bat and rat are in general much smaller than the spider, bear, ...). The form itself provides high AC but rather low damage output. It kind of feels odd to me that such a large beast does rather tiny bites. Maybe the totem polymorph form should be reduced a bit in size to reflect that it is hard to hit but does not hit too hard.
Finally, one idea I would like to put out for discussion and consideration. This is subject to personal taste, but how about changing the Epic Plant Form's appearance to the totem animal similar as the summons (same stats just different appearance). A major part of the totem druid experience to me is to be able to hunt in the totem form, and the epic plant shape is much more viable for combat in comparison to the polymorph totem form with its limited damage output.
With the Deep Shambler's Hide/MS bonus, this would additionally allow to shift into a sneaky totem animal (in my eyes very suited for rat, bat, panther, spider hanging on the ceiling etc.).