Steve Young and Fran Tarkenton were more along the lines of throwing QBs with scrambling ability. They were way more accurate than guys like Watson, Mariota and RGIII will ever be
Tarkenton's career passing accuracy is 57.0%. Of his 18 seasons in the league, 5 were above 60% (1 was below 50%).
RG3's career accuracy is 63.3%. That's higher than all but one of Tarkenton's seasons.
Mariota's career accuracy is 61.2%. That's higher than all but three of Tarkenton's seasons.
Watson's "career" accuracy (such as it is) is 61.8%. That's higher than all but two of Tarkenton's seasons.
Even below-average QBs of today have FAR better accuracy than the legends of Tarkenton's era.