Real estate question

I’ve always been interested in diversifying outside of the market
with real estate, but never had an interest in managing properties. I’ve
always asked my landlord/friend to keep me in mind with opportunities.
He’s proposed we purchase a 12 unit property, but I would be the putting
down the majority of the down payment ~70% on a 20 year mortgage and
I’d be repaid using a ‘15/50/50’ method such that I receive I assume an
additional 15% of total monthly income until the difference is accounted
for. This is projected to take a little more than 7 years and then
after that everything is split 50/50 including profits made on thé sale
of the building. Of note, he’ll also be providing property management
and we’d split all expenses. I know this only scratches the surface,
but from 1000 feet does this sound standard?

((Im still trying to wrap my head around the numbers (vs a typical
market return) which I’m happy to provide It seems like the worthiness
of an investment like this very much depends on the actual property
value in 20 years as the cash flow provided will not come close to
returns in an index fund earning 6% over that time frame. Given the
nature of this housing market I tend to think the appreciation on this
particular property will not match the 4% growth our area has
experienced over the last 20 years.))