It was during the 1940s and 50s that the Post's policy regarding cover art shifted from a vignette style (subject matter surrounded by white space or a single background color) to fully detailed paintings. This was in contrast to the contemporaneous "big face" style of women's magazine story illustration by Coby Whitmore and others, where backgrounds were usually sketchily indicated.
To be a cover artist for the Post was the pinnacle for an illustrator, the top of the totem pole. So to enter this elite group during the decades surrounding 1950, one had to paint fully detailed scenes. Rockwell transitioned to this mode, and newcomers accepted it from the start because it was a major road to commercial success.
Stevan Dohanos (1907-1994) was one of those newer artists, and he had great success, painting well over 100 Post covers. His Wikipedia entry is here, a site containing examples of his work is here, and a little more biographical information is here and here.
The consensus of opinion is that Dohanos was a skilled realist who was fascinated by everyday items such as telegraph poles and fire hydrants. One observer suggested that, unlike Rockwell, he was perhaps more interested in the setting than the people and actions that he was depicting. Ernest W. Watson in his 1946 book "Forty Illustrators and How They Work" quotes Dohanos stressing how exhaustively he researched his illustrations.
Dohanos left school at age 16 and received little formal art training, making him yet another example of a self-trained artist who did well. Apparently he engaged in fine art as well as commercial work, but nothing of note in that field turned up during a Google image search.
I find Dohanos' illustrations to be technically very well done, but they otherwise strike me as being conventional. So I'm offering faint praise. I find nothing wrong with his work, yet can't get excited about it either. For me, he deserves respect, but doesn't quite merit admiration; he was one of the good ones, but not one of the great ones. However, I am pleased that he found success during his lifetime.