The comparison to other "therapists" is a strange one, although OT isn't a horrible comparison for a masters-level MH therapist. ST wouldn't be a bad comparison, either. But comparisons to radiation therapists and respiratory therapists isn't really apples-to-apples. I'm sure the union also understands it could be a matter of reimbursement for services provided; if they had access to numbers for what the providers were billing vs. what they were paid, that could go a long way.
The difference between what the union asked for in hours vs. what Kaiser said they asked for seems pretty damning.
RE: the pension, I think someone else up-thread mentioned that they stopped the pension at the providers' requests...? Personally, if they provide access to a 401k, I don't think the pension issue is huge (unless there's a substantial discrepancy in benefits and/or Kaiser has basically said the pension isn't fiscally viable to continue, so they've had to phase it out). But it's a negotiating chip, I get it.