Pay down existing rentals vs cashout refi and add leverage?
I have three SFH rentals at this point and am in a good spot financially. One of the rentals is fully paid for and I'm torn between simply using the cashflow from it and the other two to rapidly pay the other two off, or taking a cashout refi on the paid-for rental and using that cash to buy two or three more at 25% down on each (so they will also cashflow about 300-500/month each). Doing the latter would improve my cashflow from that paid for unit from 1000/month (for the paid for house left as is and cashflowing) to about 1250-1400/month of cashflow with the cashout refi used to leverage 3 more properties.
I intuitively understand that the refi method will in the end make more money, since I'll have increased my house numbers by 3 (from 3 to 6), adds ~450K to my portfolio in house values (each being roughly 150k) and will have renters paying down the mortgages and also covering taxes and insurance as well. But I also understand that this increases risk, as all 6 houses still need maintenance, etc.
Somebody help push me off this fence!