You're using "commemorative" in a very literal sense. In the coin world they are often just designs created to be sold to collectors rather than as currency. I would class the 1951, 1953, and 1960 crowns as such, even though there was no specific event on them unlike the Churchill.
As for wreath crowns being issued for 9 years, that was only because the 1927 was very popular with collectors and the Mint saw an opportunity to make money (hey, what a concept!), which accounts for the very low mintages; why else do you think so few were minted? I've read that the 1927 was originally planned as a one-off, which indeed makes it a "commem" or whatever you want to call it.