I wanted to show you this worksheet that I used today while teaching my Online Uncial Class. I was using the 5.0mm nib end of a Zig Marker (the pink lettering) to show differing X-heights.
Normally, Uncial is lettered at 4 nib widths high and at a 30 degree pen angle. You can see the example of that with the first "IT."
The other "ITs" use different X-heights, the one on bottom left is 6 nib widths high, the bottom right is 3.
All of them are lettered with a 30 degree pen angle, with the same strokes.
Result: They all look the same, structure-wise. But the height will give a different feeling to whatever it is you are lettering.
This was fun!
Oh, and the other stuff at the top - a Pilot Parallel Pen was used to letter different Uncial A's, T's, etc.