On request I can put you in touch with a British mountain leader, Sam Benson. Sam operates in the Picos de Europa. He is well qualified as a mountain leader (MIA, ML, SPA) and has led walks and climbs in many parts of the world, including treks to Everest Base Camp and Kilimanjaro. (But he also offers less demanding programmes!)
Sam has guided for many different operators, but works independently in the Picos. He will discuss programmes with you for you and your group to suit your requirements.
To get in touch, just send me an email on firstname.lastname@example.org