You need to define the type and history of your railroad , HO , HOn3 , HOn2 1/2 ?, where ? and you have the when . If you going with a fantasy line , You might choose a "hand me down" approach , if its set in Montana you might want Great Northern types, Colorado , D&RG might be more suited .The old MDC Rounhouses are circa 1880 -90 and would have been used though the twenties. There was no USRA 2-8-0 , by the 1910's most roads were opting for 2-8-2 s or bigger for new , and 2-8-0s would out of mainline work and into branchline work . S160s weren't built until the 40's and weren't that common in the US. Of course there is brass and , BLI has or has had H10's. I am not sure what the Bachmann represents , it looks turn of the century to me.
So to decide on motive power and rolling stock , you need to develope a bit of back story for you road first and that will lead you to where you need to go.