Yes - as they are new plants I'll dig out 1or 2, if roots are very deep will herbicide the rest.. Skeleton weed is everywhere - I noticed it growing in the drain along Kent St.
It is hard to decide which weeds are the most important to get rid of. If it is a new or precious location then try to eliminate them. Chondrilla juncea was a declared noxious weed as far back as 1935, along with Paterson's curse and St John's wort.