Like Folding@home, SETI@home, Bitcoin, BitTorrent (sort of)? Nothing is quite lightseconds apart on Earth, but if you can split up the work in a way that there's no overlap, and if it's okay that the work is completed at different times, then I don't see the issue.
I'd be surprised that this was necessary for a series of spaceships to do, but I guess there's no limit to the variety of events that "spaceships" could be dealing with.
For a different analogy, we have instruments all over the Solar System that people work on all day (and sometimes night, e.g. going by Mars time), and they have to deal with up to hours of delay.
Edit: Overlapping work would be okay if you had a time sensitive problem to solve that it would take a different amount of time each time to solve. Or if you can have each computer try a different way of solving a problem, when you don't know which way is the fastest. Meaning that one of the computers might solve the problem faster than the others, but you don't know which one until it gives you the answer.