My question is, is 56 coins too many? Do you think I would be better selling some to increase my holdings in the other coins?
I think it depends on your goals and your resources. Is diversification sufficient or do you want to select and manage individual investments, or something in between? Are you investing for the long term or the short term? How much time do you have to spend on your investments?
In terms of diversification, there is no "too many". If you are going for diversification, then more is always better. However, most cryptocurrencies are highly correlated, so the benefit of diversification is limited after some number of coins.
In terms of managing individual investments, I don't think anyone has the time to follow 56 coins, unless you do it professionally, perhaps. If you invest in 56 coins, you are effectively investing in random coins. In my case, I don't think I have the time and patience to follow more than 2 or 3.
As for looking for something in between, I believe that in the long run there will only be a few big winners, but many big losers. By weeding out the big losers (many of which are obvious), you can get better returns with only a small impact to risk.
In my case, I feel that investing in the 5 (or less) highest quality and least correlated coins is better than investing in 56 (or more) random coins.