@Steve Mcdonald There are a couple elements you might want to check into in greater depth1.

Just hard work combined with diligent saving and time.

I've been an IT and Construction project manager for years so I've put together a really good team consisting of multiple general contractors, real estate agents, social media consultant, wholesalers and a local design firm to complete our home layout and design elements.

Combine this with a mortgage and it's near impossible to get ahead.

Hawaii's population is very debt adverse so people are very fiscally conservative... that combined with the fact that the ohana comes in and helps if anyone falls behind.... means little to no foreclosures.In addition wholeselling is extra tough because Hawaii just has so much dumb money and international money chasing non cashflow deals that don't make sense.

What if a combination of these issues happen all at once? 

Amazon and Alliance Bernstein were the biggest announcements of new firms coming to town and are supposed to bring a combined 6,000 new jobs to the area with an average pay of $100k or more - as it stands, those jobs have yet to arrive.

The 3-Family and the Single Family now comp separately rather than combined against a 4-unit house in a worse location with smaller lot size (as had always been the case).Added roughly 250k+ in combined market value.Lessons learned?

This deal is due to combination of luck, timing, negotiations, etc. to get to current shape.  

A blanket loan will not lower your dti because the loan amount would be the combination of all 4 properties, which is the same as them being separate.