The silver shilling, was the most popular denomination minted thru’out the Commonwealth period. It’s production was in no way linked to a gold denomination.
Another interesting obsevation is that in general hammered gold unites were well made compared to silver halfcrowns. Rarely does one see a double strike on gold coinage. On silver it’s the exact opposite situation with very few pieces being made without the appearance of either double strike or off centre striking. We know that making a halfcrown involved four to six hammer strikes. Maybe the gold unite on the other hand was produced with one good strike on the softer, thinner metal.
At the other end of the spectrum, the toughest coin to strike was most definitely the silver crown. With a surface area of 1384 square millimetres compared to a halfcrown of 907 millimetres, and a greater thickness, much more striking pressure was required to make the crown. The typical quality of a hammered crown however was comparable to that of the unite. One other reason for the relatively poor quality of the halfcrown might have been the production numbers. Typically three times the volume of halfcrowns were produced each year when silver crowns were also made. Crowns were much more uniform in weight as well. I have yet to see a low weight crown whereas some halfcrowns are 6% or more below target weight.
The gold crown, had the smallest features of all the hammered coins, The lettering was especially difficult to accommodate on the obverse side where often stops are eliminated or the D of ENGLAND is omitted so that the legend would fit in. The cross hatching on the shields must also have been very challenging for the die maker and is usually seen as poor on the reverse. Of the gold production this appears to have been the most unpopular to make. Initial enthusiasm is seen as tapering out after 1654.
As a general comment, the highest quality coinage where one generally sees good weight and quality of strike, involve all the gold coinage and the silver crown. After that coins for daily use of merchants, typically halfcrown and lower are often poor weight and poor strike quality. As regards size, it appears no changes were made during the Commonwealth period. Design variants were the order of the day.