> Thanks for the reply!
> BTW, why some of the unofficial artworks are not added to the official set? It would
> make sense having one complete set, don't you think ?
Official artworks are made by the MAME (and MESS) artwork team and intended to be high-resolution reproductions of the bezel artwork, overlay artwork, background artwork, and even marquee and control panel artwork, of the games in question. Some of these are from extremely high-resolution scans, others are completely vectorized.
Unofficial artworks are not intended to be reproductions, and are instead things people think "look cool", or invented out of thin air. They often do not have referenced the original artwork in their creation. Frequently they are intentionally different from the artwork the games actually used, such as altered to cover more screen area on widescreen monitors, etc. Often the people working on these are not the same people working on the official artworks.
So no, having one complete set could confuse people into thinking that invented third-party artwork was identical to the artwork games originally used.
What AntoPISA is doing is a good compromise. Mixing them as you say could cause confusion.
I hope this helps you understand what you are asking.