Just starting to mine

I have a rig of 1660’s. I know RVN isn’t most profitable, but I have a theory that when ETH goes to PoS that some other coins (looking at RVN and ERGO) will get more hash power and hopefully increase in profitability. So, I can mine cheap coins now and get a payout later. Is this good thinking? Currently mining RVN with a 2070, 8x1660s, and a 1660 super. Is this a good strategy? Or maybe I should try another approach?