I recently finished Dr. Shea's book on the battle "Fields of Blood", and highly recommend it. It has prompted me to study more on the IHG units there. The 1st IHG was on Blunt's left. One company of the 3rd IHG, "the Pin Regiment", was on his right. I think the balance of the 3rd was with Blunt's trains at Rhea's Mill, about 6 miles northwest. I don't recall where the 2nd was.
On the Confederate side, the only IT troops there may have been Bryan's Battalion, which was attached to Marmaduke, but they may not have seen combat as they were acting as pickets. Watie and Folsom never made contact with other Confederate units. They moved up the line from near Evansville and ventured a little into Arkansas but, not finding Hindman's army, they turned west and attacked a group of Pins at Manus' (which I believe is east of Park Hill across the Illinois -- not sure) and then returned to their camps; Folsom to Scullyville and Watie to Webbers Falls.
I thoroughly enjoyed the reenactment and chatting with the reenactors. It was winding and got cold quickly in the afternoon but totally worth it.
I'll post some pictures when I get the time.
Ken