If they pass all of the checks and have the proper income then they have a shot at moving in.

It's great for a landlord if the tenant is properly screened. 

@Andrae S Wiggins recommend you upgrade your BP membership to Pro to access the BP Calculators to evaluate rental purchases.Play with the numbers to figure out the purchase price that gives you your target ROI.That's the number you'll need to make an offer at, NOT what the seller is asking.Yes, you will get a lot of rejects, but whoever said investing was easy?

Obviously each deal is unique and requires proper due diligence. 

How difficult or easy has it been to get tenants secured in that area?

It is very easy and doesn't have to be contentious. just follow the steps.

How would you recommend, or what resources would you refer for us to properly figure out how we spend our time and appropriately get compensated for it?

The guru your son is learning this technique from is likely not telling your son that the deal will almost certainly encourage your son to get an "off-market" deal from a "wholesaler" who is unlikely to properly disclose the details of the property or encourage an inspection. 

It’ll give you an easy to read view of how many of the points raised by Dan H and Chris S play out in a deal. 

I don’t know how easy it would be for you to contact every resident and ask that nobody use any water at a certain time for 10 minutes.