I'm definitely late to this party but.. Eloqua does re-order step types ie) contacts before CDO and fire in the order listed.
However I recently ran into an issues when updating custom data objects with Form data and custom values.
After a long and painful troubleshooting session in trying to figure out why our CDO record wasn't being created, it was pointed out that our update with custom values was ahead of our update with form data (which creates the new data cards).
d'oh.. so much for thinking there was an auto-re-order by Eloqua to cover all scenarios !!
Since there wasn't an ability to drag to re-order, we had to delete all our CDO steps and made sure the update CDO with form data processing step was created first.
..