What separates a Hard Money Loan from a Private Money Loan is often as simple as the rate charged. PML can charge HML rates, so they get called HML.
PML are usually "kinder and gentler" and are individuals lending their own funds.
HML usually are business oriented and have a hierarchy and overhead. Many are brokering deals to PML and/or using their own credit lines or fund.
A good question to ask is "are you lending your own funds, or are you brokering this deal?"
Let them know you are happy to work with a broker, because many add value. If you access someone lending their own money, you will usually be able to have the flexibility to create a win-win for you both.
Several PML can be on a note together. I have done this with PML that know each other, i.e. Husband, Wife, Children. I would not advise putting lenders together that don't know each other even though it can be done. The risk is not worth the gain. Better to find that one PML with enough for your deal.
If you have a large deal that warrants the legal expense, then you can look at a syndication or other options similar. Not on a small to mid sized flip though.