arkryal vlatro

Picture 1 looks like some type of nettle. Not stinging nettle, but there are many varieties.
There are also a few members of the mint family that look similar.
What shape is the stem? Round or square?
Does it have a strong odor when crushed, or does it smell light and sweet (like cut grass)?

Does anyone have information regarding how comparable to Comfrey other members in the Boraginaceae family are in terms of their usefulness?
I ask because I have a lot of houndstounge in my field. Is it worth propigating for use as mulch and composting?
The growth rates are better than cultivated comfrey in my region. It seems better adapted to cold, heavy clay soils and being water-logged, which is the best description of my land.
I'm just unsure of the plant's composition and habit. It seems like a viable substitute, but I'm unsure and have found little in the way of literature on other plants in this family being used similarly.

I also have something comfrey-like growing that I have yet to identify. There's probably a quarter acre of it. I want to know what it is before I turn my sheep out on that field.
It looks similar to the bocking varieties of comfrey, but has a serrated leaf rather than smooth. True comfrey doesn't grow wild in my region, and this is clearly not that anyway.
I asked on another forum and someone told me it was burdock, (obviously not), so I figured I'd ask here and see if I can get an expert opinion.
I can rule out houndstoune, I have enough of that growing to see the difference. This has the hairs on the leaf, though the photo doesn't show them well.
Thanks in advance.

For scale, the leaves here are slightly bigger than my hand. maybe 6" wide by 9" long.

Region is western NY, bottom of Zone 5.