Xref / Scaling / Dimensions

Hi, I had an AutoCAD project (which I attached in pdf form) back then where I was supposed to draw the profile view of a bridge and a cross-section view of a bridge onto one sheet along with the title block. I remember doing it by scaling the dimensions myself by hand then drawing it according to my scaled dimensions. I drew both of them together in the same model space. Now that I'm more familiar with Xrefs, I was thinking if there was a better way to do it.

I was thinking about drawing each separately (in their own files) according to the real dimensions. Then I xref both into a third drawing. I want the scale of the profile view to be like 1":20' (since the bridge is like 150' long and I'm using 8.5x11 paper) and cross-section view to be like 1":10'. Should I scale it in that pop-up window when I attach an xref? How would I go about dimensioning it as well? I tried to dimension in model space of the third drawing, but it only shows the dimensions after scaling. Or should I dimension it in the original drawings before xrefing? Should I use annotative dimensions?

Edit: I cleaned up the questions a bit so hopefully it's easier to read.

Scaling: Should I scale in the pop-up window when attaching an Xref or should I simply scale in the viewport of paper space?

Dimensions: Should I add the dimensions in the original drawings, the model space of the third file (host file of the xref), or paper space of the third file?

I tried scaling in the xref pop-up window and dimensioning in model space. However, with that method, the dimensions that are shown are according to scale, not the real dimensions. Also, the dimensions are super small so I was thinking using annotative dimensions would help.

Thanks!

1. General Plan.pdf