I found out that the 30% federal tax credit applies to the entire project price regardless of any incentives.

So the revised math would be:

$5493.67 total project price
$1828.74 Oncor incentive
$1648.10 30% federal tax credit

$2016.83 total cost of project to homeowner
36.7% Percentage of total cost to homeowner
30% Percentage of total cost from federal tax credit
33.3% Percentage of total cost from Oncor incentive