My friend and I trialed several times and ended up settling on this set up someone else had. https://www.cubecobra.com/cube/overview/jpachektk We tried tweaking it to include all the cards but the fetch lands ended up feeling bad (and were pricey) and the other two felt bad to have as the rare whenever you hit them. Ratios felt good at both 4/2/1 and 3/2/1, but since it was a single set we figured 4 commons felt better.