Want to scale up, but need some advice.

[Corey Key]

Good day BP

I'm between a rock and a hard place on making a decision. Currently I have six properties three in California and three in Louisiana. One of the homes is being used as a primary residence the rest are rented out by tenants. After reviewing the market data I see that I have roughly 794K in Equity in the six homes give or take if I sell. I would like to scale up and purchase a couple multi-families and/or a apartment complex by taking out a cash out refi approx. 300-400k on three of the homes in California since they are sitting with the most equity and use that as a down payment for a multi-family since the interest rates are so low. I was speaking to my mentor about it and he suggested selling the homes then buying a multi-family, I'm trying to understand his point about selling. Why sell when I can continue getting income from these rentals especially since they are tenant occupied. Why sell the cow when I'm still receiving milk especially on the homes in California. I definitely do not want to keep the equity sitting there not performing,  So I guess the questions I have are

1. Should I sell the homes vs. Doing a cash out refi to put down on a multi-family.

2. Can I do a cash out refi on multiple homes at one time?

Still a beginner to investing in Real estate so looking for advice on moving forward. 

Thanks