I'm just curious why you've quoted the two random posts you have quoted and what the rest of it means.
There's no Ruf cars that can accept new engines, so they're not listed. A Ruf-origin engine can go into two other cars and that is listed, under "Ruf" in the engines list. The car ordering isn't really relevant to anything - and is inconsistent in the game in any case, so I've done it in a more comfortable and easy to browse format (adding and rearranging some information to make it more clear and consistent): alphabetical, then generational where at least some cars have a generation listed, then alphabetical again. And the Toyota 86 Gr.4 is listed as such, twice; there are other non-racing 86s in the list too.