Perhaps they are not Danica?

if your only alternative.. is removal due to size .. then give it a go.. whats to lose ...

you really dont mention how much you are thinking of removing at once ...

ken

Shear conifers late spring-early summer. As in right now. If you already want these to have small tight shapes shearing them probably won't make them look too geometric for the effect you want.

Cypress family conifers such as arborvitaes are generally plenty suitable for shearing, look at the very tight Leyland cypress hedges that have been produced. However no frequently grown conifers except yews lend themselves to cutting back into bare wood. And if your 'Danica' are so much bigger at this point than what you want that you would be shearing the entire outer shell of foliage off then they should be transplanted or discarded anyway.

As anticipated an image search turns up pictures of examples of 'Danica' that are of apparently greater size. Even dwarf variants of conifers could be expected to live some time. To not exceed a 2 ft. space one of these would have to be a miniature kind or die comparatively young.

https://images.search.yahoo.com/yhs/search;_ylt=AwrTcdzUzEJZJSwA8HoPxQt.;_ylu=X3oDMTByNWU4cGh1BGNvbG8DZ3ExBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=thuja+occidentalis+danica&fr=yhs-avast-brwsr001&hspart=avast&hsimp=yhs-brwsr001