As I posted earlier in comments, probably (?) you will be able to find someone who speaks somewhat understandable English and could try to negotiate a tandem with them. I've never been to the area but e.g. at Kumbum monastery there were guides with good English and many Tibetans I met in Qinghai spoke decent to better-than-mine English. Some luck might be necessary but if you ask around you could find someone. Given the beauty of the area I would defs go and try.
Alternatively It might be worth a try to contact Jamin “Lobsang” Lee of The Land of Snows. He is an expert on Tibet, working for NGOs, has a travel agency and author in many guidebooks, including the Lonely Planet which is the only book I fully recommend for China. But most importantly he claims on his website:
Understanding how difficult it can be to get accurate and current travel information on Tibet, Lobsang started The Land of Snows website in 2006 to assist travelers in planning their journey to Tibet. The site now has over 25,000 visitors per month. Lobsang receives nearly 3000 emails per year from across the globe from travelers asking him for advice on which areas of Tibet (and other areas of the Himalaya) to travel to and how to get there. Free of charge and regardless of which travel agency they use, he answers nearly 95% of these emails. To contact him for travel advice, send an email to: email@example.com
If that last part is true, it would be worth a try to shoot him an email and ask if he knows a suitable person in Danba.