When I moved into my house there were a lot of conifers in the garden, and some were crowded in together. I chopped down a few that were obviously wrong immediately, and they all had the same number of rings, so it was obviously an "arrangement" done which probably looked nice for a couple of years but soon became ridiculous because of the differing growth rates. As I've watched them grow over the years I've removed more and more of them, though I've kept a few that aren't too big... yet.

There are some conifers that will still be less than a couple of feet high after 50 years. So maybe they will be too big one day, but that one day is a very long time away. My neighbour clearly knew his plants because he has a miniature conifer arrangement and they are still all small plants and they have been in at least 20 years. He's a retired professional gardener, but he reckons he has to ask his wife to choose the plants.

Incidentally there do appear to be a few more conifers than just yew which can be clipped back like a hardwood bush and will regrow, because some of the ones that used to be in my garden behaved like that when I tried clipping them back, they just regrew even faster. But on the whole they aren't so common.