Two x JR Pass - possible? and when to activate

I'm visiting Japan 30 March to 19 April 2023 inclusive - 21 days.
I'm on a tour 31 March to 13 April and 14 day JR Pass is included in the tour cost and supplied by the tour company.
I intend to buy an additional 7 day pass which I would activate on arrival 30 March. The 14 day JR Pass supplied by the company, I would activate on 6 April which would take me to 19 April inclusive. Is the above possible?

After the tour ends in Tokyo on 13 April, I am visiting the Kiso Valley with trains Tokyo- Nagoya - Nakatsugawa - Magome then walk to Tsumago and train Nagiso - Kiso Fukushima - Narai - Matsumoto - Nagano -Shinjuku, Tokyo - Narita Airport.
The Kiso Valley trip is over 5 days and on the final day I'm travelling from Matsumoto to Narita Airport, with my flight departing at 1830 hours with check in 1630 hours.

Can I buy and use JR Pass as above? Does my Kiso Valley trip make it worthwhile to buy a 7 day JR Pass?