To fix the issue with the services I ended up reinstalling the manager on the problem node. This caused things to work properly within SMSP, however after messing around with NLB for far longer than I should have, I have abandoned this solution.
It says in the document this should provide a level of HA to the SMSP manager. I think it only provides load balancing. When either of the nodes were offline, the Docave manager would hang on login, eventually timing out. When that system came back up, logins worked fine again.
This may have been an issue with NLB convergence, however weighing all variables I simply abandoned HA. Our Sharepoint environment is HA, the SMSP manager doesn't need to be HA given we only have about 4 SMSP admins.