Hello, Brad. I'm assuming, since you say the client names appear on the jobs, that what you're actually updating is the client ID fields. If that's the case, here's what you can do:
1) Create a relationship (temporarily) between client and job based on the name. It can be an additional TO on your Graph (that's what I'd recommend) or you can just change the default relationship (again, temporarily).
2) Use Replace Field Contents to insert the ID, using a calculation of ClientByName::ClientID. This will automatically populate the client ID field in all the records with the appropriate value wherever there's a match based on name.
3) Do a Find for any that still have empty IDs. Fix them manually.
There's a caution here: Make sure you don't have any duplicate names, otherwise you might end up with the wrong ID being inserted.
Thanks Mike, that worked perfectly.