I did not know Martin, but he looks to be a big Steve Ditko fan.
I recognize Russle from back in my collector days. I would say his work generally hits the target for me, but like some of his contemporaries (Broderick, Willingham, Golden) his anatomy learns towards the stylized in a way that sometimes work for me, and sometimes misses.
It may not have been entirely their fault. I have read that art schools in the late 60's and 70's went to pot (no pun intended) as the counter-culture took them over. They stopped teaching in the classical manner and it became more about "finding your personal
style". This was partially a response to the collapse of the commercial illustration market as photography took over in the magazines and ad industry. Folks like Ronald Dahl and others before him has success in the children's literature market with a stripped-down and simplified (abstract/child-like) style. The emphasis turned to finding a personal style such that learning realistic anatomy etc. were ditched as "too confining, man". Interesting how that generation always justified avoiding hard work.
There has been a fairly recent trend in art schools to get back to the Atlier, Golden Age of Illustration, style of education (late 19th century, early 20th)---which sounds very hopefully to me. I think this next generation is really going to shine now that some of the lingering after-affects of the Baby Boomer's relativist/do-as-you-will/if-it-feels-good-do-it mentality is starting to fade in the educational system momentarily.
Barry Windor Smith's latter work is great. No doubt.