Diversification can be simplified relative to the relative cost - selecting top 50 that is below a dollar, within a dollar to ten dollars. Alas the so-called market cap is not entirely true or measured correctly. For instance many coins lost, or the new Bitcoin Gold, satoshi won't be using his coins so those are still calculated in the pool.
I'm not a big fan of judging cryptos on the price, I mean look at $XRP and $BTC. They couldn't be more different in price. The market cap is the best basic indicator of how much the world is invested in the currency, which is why I use it as a breakpoint for risk. Agreed on the distinctions, e.g. circulating supply vs total supply, escrows etc, but that data isn't readily available for spreadsheets :)