Everything completely depends on the make and model of the projector you are using. In reality, you are going to have focus issues because projectors are designed to project onto a flat plane. Anything in front of, or behind, that plane will be more and more out of focus.

You also will be projecting onto a curved plane, which will introduce warping into the image, which will need to be corrected for.

I'm not sure how many projectors offer the short throw you need along with warping capabilities, but it is worth consideration to look for if you don't have the projectors already.

If you do, then any functionality and loss in image quality due to needing to apply both horizontal and vertical keystone correction should be considered. Some projectors offer 4-corner keystone adjustment, and that is what likely will be necessary if you locate the projectors slightly off to the side of center. Be aware, that this impacts throw distance as well.