Maybe instrumental talent. Mickey had one of the great pop music voices of the 60’s. His vocal rendition on “Going Down” is awesome and he did it in one take. On most early Monkees songs Mickey is the only one from the band you are actually listening to. The rest are all studio musicians.
I think they were all decent musicians, though not on par with the Wrecking Crew session musicians who played on their records. Supposedly, Mickey was the best guitarist when they formed the group.