Should you host similar affiliate sites at different hosting companies?

Google might expect that you'd simply set up 1 really good affiliate review website instead of a few.

My answer would be different than the OP's. I used to host all my sites with one host. That host literally disappeared overnight, taking down over 100,000 websites with it. I was out of business with all my sites. If I had them spread out over multiple hosts as I do now, I would have only had about 25% of my sites go down.

By the time I got all my sites back up and running I lost a lot of sales. I found $200-300 a year in additional hosting fees to be pretty good insurance.

It's paid off a couple of times. Once when a major storm hit the city where some of my sites were hosted it knocked the host out of business for over a week. Their back-up power was wiped out too, so those sites were out of business for that time, but my other sites kept functioning and bringing in sales.

Another time was when EIG bought out a host and the sites hosted there were routinely broken until I moved them. Again, most of my sites kept functioning and bringing in sales because I had them spread out over multiple hosts.

Not exactly what the OP was looking for, but I thought I'd mention it since it's a good reason for using at least two hosts. I use four.