Jeez, you can't get a break, can you! I'd say security cameras or trail cameras to get a license plate number. Maybe beware of dog signs? Even if your dogs aren't super ferocious that'd help?
I put your picture into iNaturalist.com and it's first suggestion was Field Goldenrod. Field Goldenrod (Solidago nemoralis) · iNaturalist
EDIT: But please, contact your local extension office to be sure!
We tried putting them together this afternoon before it gets cold and slipperier, and before the rain hits tonight.
We gave them each a small pile of hay on opposite sides of the barn then left both gates open. Diva got done eating first and went over by Mom in the barn, Squirt took longer to...
How long did you keep them separate? We got our second mini back on Nov. 22nd and she is more bossy/nippy than Squirt and we tried to put them together for like 5min. but they were kicking and squealing.