So... Then I guess that means it is safe then right?

The whole point of crypto is that you are relying on the fact that 50% of the network is honest.

So yes, you are correct that it relies on half the network being "benevolent". That's how ALL cryptos work.

You are missing the point. Bitcoin and Bitcoin Cash use the same hash algorithm. Bitcoin Cash has about 15% of the total available SHA256 hashpower, and Bitcoin the other 85%. So it only take's a fraction of Bitcoin's miners to turn against Bitcoin Cash to attack it.

Yes, and the Bitcoin network ITSELF can be attacked with a faction of the total hashpower on the Bitcoin network.

Specifically, the fraction is 51/100, or 51 percent of the network. This is for the main Bitcoin network.

The fraction for Bitcoin cash would be around 15%, or 15/100, expressed as a fraction.

The Bitcoin cash network would require a smaller fraction, yes. But this still isn't a huge concern.

If it is 3 times easier to attack bitcoin cash, that is still extremely difficult.

Fractional hashpower attacks, (51% attacks) are all explained quite clearly in the white paper.