I would be more concerned about determining the status of the key systems, e.g Roof, electric, plumbing, Hvac e.t.c.

Case law has determined that a property owner may have an ability to assess the total value of a property but doesn't hold any special qualifications to determine the split between land and building.

The predict the future product, but still apply past data to determine the value.  

I have partners and professionals with my MFHs, so that will be determined later and probably handled differently.)

You can use those results to determine if they're worth the time it takes to do a showing.

They can tell you what to look out for and inspect the system to determine the condition. 

Also,  they aren't able to determine how much life is left on a roof.

How do they determine how much you get?

The tricky part is vetting the good from the bad and determining who is actually direct to the capital.For the state of California, it is easier to vet a "Broker" that is not direct to the capital vs. a "Hard Money Lending Company". 

So I guess you should determine which market you want to be in, what type of househack you want to do, and how you want to execute.