Should a line have enough roundhouse space for all of its steam locomotives?

[BraselC5048]

Pretty much a research question - should a shortline have enough roundhouse or enginehouse space for all of its steam engines at once? If not, what should the ratio be? And if it owns, say, 8-9 mallets, how many stalls/"mallet house" spots that fully fit them does it need? Is 3 enough? (What if the remainder of the stalls only the last 2 feet excluding the coupler doesn't fit with the doors closed?)

Thanks.