After I built my 30" turntable I didn't have room for a roundhouse in the 2'X5' area I had for locomotive storage. So I built and am currently in the process of finishing a 22"X34" engine house. So that's an option if you don't have the space for a roundhouse like I didn't.
Your setup reminds me of CSX's Russell , Ky. location.
Of course theirs is much larger , but the same idea.