I assume that is where a good portion of the variance is coming from.Great job diving into the numbers on the properties as that is always good practice and allows you to better understand what numbers you want to input on the various types of assets you explore investing in. 

So in practice, an annual lease term seems one-sided for the tenant's benefit.

I've been practicing by analyzing 1 deal per day and I have a very general grasp on all the factors that must be taken into account and the process, but I wanted to know what everybody else does first and how they identify a good deal before they do a deeper dive.

Those skills are acquired through people imparting knowledge that can be implemented into practice.

Even if you're not quite ready to buy, you can start practicing with running your numbers, which an experienced agent can help guide you on. 

"for rent by owner", investors)-search for non-homestead properties in your county and send postcards to those owners that own homes that meet the criteria you want to focus on-network with real estate attorneys -network with trustees in banks that offer trustee services-look up court records of landlords who have filed their own evictions and send them postcards -network with HOAs that have non-homestead properties in that association -when you see a "for rent by owner" sign in your area, send the owner a letter -join Facebook groups (for rent by owner, landlords) and being to contribute -improve your SEO on your website-find someone who can help you gather landlord info from Zillow, etc.

I've digested a lot of knowledge and practiced running numbers over the past few months to the point where I feel well equipped (enough) to take the plunge.  

I mean your story is not only motivating, but it’s unbelievable practical, humbling, and again phenomenal.

Best advice is to reach out a septic designer and see how many drain fields you would need, or how many homes you can combine into 1 field based on code & practicality. 

None of the above works unless you take action and put it into practice.