Arnold has 6 major hits in a 40 year career... Lee Marvin & Bronson are certainly not as popular as Arnold, but they have influenced the action genres far more than you think.
I'm not a big Bronson fan myself--he did some gawd-awful films in his later years. But he had his day and legions of fans and again a bigger range or roles than Arnold.
Each generation assumes the world they know is bigger and better than anything that ever came before--it's only as one ages and develops a sense of history that one begins to see the value of what came before. Meanwhile, some think Arnold hung the moon simply because they saw all of his films as kids, with few previous examples by which to judge him.