Minor math error there with your DUK-WI calculation.
At the share prices you quoted the values of DUK-WI is $19,080 and SE-WI is $14,125 for a combined value of $33,205. Which is $135 ahead of the value of the hypothetical 1000 DUK shares.
My tracking shows that since DUK-WI and SE-WI started trading last Thursday they have consistently been worth more that DUK alone.
Beyond this observation I have no clue what's going on here or how many -WI shares are in play. Any thoughts on whether the -WI share prices reflect true market valuation or is this being managed somehow thru the split date?