I'm also confused what is the purpose of running two delivery creation processes at the same time and why is it required for an order ro be processed by both instances.
When delivery creation starts, the whole order gets locked - it's a standard functionality. One (but not the only) good reason for this is that delivery creation also updates order status at both line and header level. How do you envision this would work with two processes updating the same order simultaneously?
Maybe I'm mising someting, but such requirement just doesn't make any sense to me from the technical standpoint.