Could I Combine Arashiyama and Nara?

I will purchase the Kansai Thru Pass for 3 days, 2 of those used in an overnight trip to Koyasan.

For the third day, I want to go to Nara. I was thinking of combining my short visit to Arashiyama and Nara, is it doable? which should I do first, Arashiyama?

This is my schedule so far for both:

Arashiyama
Moneky Park
Arashiyama Park
Togetsukyo Bridge
Bamboo Groves
Take Sagano Scenic Railway (this could be dropped)

Nara
Nara Park
Kofukuji Temple
Todaiji Temple
Todaiji Museum
Yoshikien Garden (optional)
Kasuga Taisha
Naramachi (optional)

Thank you.

I was thinking of combining my short visit to Arashiyama and Nara, is it doable?

If you start your day very early, drop all the optional sights and travel at a fast pace, it can be done. Otherwise, it is not possible.

Personally, I feel it is not possible. The amount of walking involved in Japan is often under-estimated: as is the time taken to travel from place to place.
Arashiyama and Nara are on opposite sides of Kyoto, so there is a lot of backtracking.
Choose one, and enjoy it at a more relaxed pace
Enjoy!

If you are staying in Kyoto or Osaka you can return from Koya-san via Nara, leaving the next day for Arashiyama.

Well I dont think you could ever spend too much time in Nara, but I suppose that if you got to Nara really early, like 8AM, you could see a fair bit - Park, Pavillion, Todai-ji, Pagoda by midday and then be on the train back to Kyoto.

But personally, I'd give Arashiyama a miss until you have the better part of the day to explore it, and maybe stop at Uji and/or Fushimi Inari instead. Each are handy to Nara and Kyoto, and a quick walk from their station.

Thank you. I will desist of this idea and try something else. Not to sound bad but Kyoto is very expensive!

I'll try to do everything Kyoto in 3 days, then 1 for Nara/Kyoto and stay in Osaka 1 whole day.