If you have time, IMO the absolute best way to do this stage, which requires no cars or pick-ups, is to follow Isabelle’s map from years ago. It is post number 8 on this thread.
https://www.caminodesantiago.me/community/threads/galisteo-arco-de-caparra.7625/#post-45550
It works the following way — Spend the night in Carcaboso. Walk the next way to the arch at Caparra, which will get you there at a time when the visitors center is open and you can enjoy the site, whose excavations are expanding. Then from there to Plasencia de Oliva is a short few kms past bull farms, off road if I remember correctly. Stay in the albergue turístico or casa rural there (you should reserve). Then the next day, walk back through the arch (no problem that everything is closed since you saw it all the day before) and on to Aldeanueva.
Gronze shows the detour to Oliva, but I would take the westernmost dotted line both ways, because the way from Venta Quemada to Oliva is on the side of the road.
Es la Etapa Reina de la Vía de la Plata, de gran belleza, muy larga pero sin desniveles significativos; podemos dividirla desviándonos unos kilómetros del camino (ver mapa). Jornada muy solitaria, por pistas de tierra, a tramos por preciosas dehesas, y a tramos por descampados o zonas boscosas...
This adds up to these totals.
Carcaboso to Oliva de Plasencia — 25 km
Oliva de Plasencia to Aldeanueva — 26
The other option is to walk to Hostal Asturias. There is a sign indicating where you should turn off, and it is about 2.5 km to the hostal. I know that some people have the hostal come pick them up at the Arch, but there have been complaints about having to wait a long time (inevitable no doubt, in the life of a busy hostal owner), and if you start in Carcaboso it’s only 18 to the arch.
Every time I post about this, I wonder where Isabelle has gone. Her map was a huge help to me, and I keep hoping she will show up again. Buen camino, Laurie